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Giuseppe CANTARELLA
Ricercatore t.d. art. 24 c. 3 lett. B
Dipartimento di Scienze Fisiche, Informatiche e Matematiche sede ex-Fisica
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Pubblicazioni
2023
- AC Performance Tunability of Flexible Bottom-Gate InGaZnO TFTs by an Additional Top-Gate Contact
[Articolo su rivista]
Catania, F.; Khaanghah, N. S.; Corsino, D.; Oliveira, H. D. S.; Carrasco-Pena, A.; Ishida, K.; Meister, T.; Ellinger, F.; Cantarella, G.; Munzenrieder, N.
abstract
This study explores the performance tuning of flexible InGaZnO (IGZO) thin-film transistors (TFTs) using a double-gate configuration. DC analysis on individually controllable double-gate TFTs highlights that the bottom-gate biasing is highly effective in facilitating efficient switching of the devices, whereas the top-gate biasing allows for controlling their performance. This is demonstrated for the ac response of the devices with different channel lengths showing the tunability of $\textit{f}_{\,\text{T}}$ and $\textit{f}_{\,\text{MAX}}$ with a maximum relative tuning up to 130% for $\textit{f}_{\,\text{T}}$ and 170% for $\textit{f}_{\,\text{MAX}}$ . A more efficient control is observed for longer TFTs, resulting in increased characteristics frequency up to 50%. Furthermore, the effect of the performance tunability is also reported even when the double-gate TFTs are exposed to tensile strain induced by a bending radius of 2 mm. These findings indicate new possibilities for the design of flexible analog systems with dynamically adjustable performance.
2023
- Feasibility of chest ultrasound up to 42 m underwater
[Articolo su rivista]
Paganini, M.; Cantarella, G.; Cialoni, D.; Giuffre, E.; Bosco, G.
abstract
After recent advancements, ultrasound has extended its applications from bedside clinical practice to wilderness medicine. Performing ultrasound scans in extreme environments can allow direct visualization of unique pathophysiological adaptations but can be technically challenging. This paper summarizes how a portable ultrasound apparatus was marinized to let scientific divers and sonographers perform ultrasound scans of the lungs underwater up to − 42 m. A metallic case protected the ultrasound apparatus inside; a frontal transparent panel with a glove allowed visualization and operation of the ultrasound by the diving sonographer. The inner pressure was equalized with environmental pressure through a compressed air tank connected with circuits similar to those used in SCUBA diving. Finally, the ultrasound probe exited the metallic case through a sealed aperture. No technical issues were reported after the first testing step and the real experiments.
2023
- Influence of Semiconductor Island Geometry on the AC Performance of Flexible InGaZnO TFTs
[Articolo su rivista]
Khaanghah, N. S.; Corsino, D.; Catania, F.; Costa, J.; Cantarella, G.; Munzenrieder, N.
abstract
The AC performance of flexible TFTs sufferers from parasitics caused by tolerances needed for the fabrication on free-standing plastic foils. In this context, the semiconductor island can either be wider or narrower than the source/drain contacts. Traditionally, the second configuration is expected to result in faster TFTs as the total gate overlap area is smaller. However, here it is shown that 2.5μ m long flexible InGaZnO TFTs with wide semiconductor islands exhibit better frequency performance such as a fT of 26.1 M Hz (compared to fT of 13.8 M Hz of TFTs with narrow semiconductor islands). This effect is confirmed for flat and bend TFTs and is caused by current spreading in the semiconductor islands, as well as the frequency dependency of the gate capacitance.
2023
- In-Ga-Zn-O Source-Gated Transistors with 3nm SiO2Tunnel Layer on a Flexible Polyimide Substrate
[Relazione in Atti di Convegno]
Corsino, D. C.; Bestelink, E.; Catania, F.; Sporea, R. A.; Munzenrieder, N.; Cantarella, G.
abstract
We report the first In-Ga-Zn-O source-gated transistors on a flexible polyimide film. Our findings show that using Au contacts and the incorporation of an ultrathin SiO2 tunnel layer facilitate contact-controlled operation, distinct from conventional thin-film transistors with Ti contacts. This was confirmed by early saturation in the output characteristics and the very low saturation voltage change over a gate voltage change of < 0.1 V/V which agrees well with the theoretical saturation coefficient of ≈ 0.1.
2023
- Laser-Induced, Green and Biocompatible Paper-Based Devices for Circular Electronics
[Articolo su rivista]
Cantarella, G.; Madagalam, M.; Merino, I.; Ebner, C.; Ciocca, M.; Polo, A.; Ibba, P.; Bettotti, P.; Mukhtar, A.; Shkodra, B.; Inam, A. K. M. S.; Johnson, A. J.; Pouryazdan, A.; Paganini, M.; Tiziani, R.; Mimmo, T.; Cesco, S.; Munzenrieder, N.; Petti, L.; Cohen, N.; Lugli, P.
abstract
The growing usage and consumption of electronics-integrated items into the daily routine has raised concerns on the disposal and proper recycling of these components. Here, a fully sustainable and green technology for the fabrication of different electronics on fruit-waste derived paper substrate, is reported. The process relies on the carbonization of the topmost surface of different cellulose-based substrates, derived from apple-, kiwi-, and grape-based processes, by a CO2 laser. By optimizing the lasing parameters, electronic devices, such as capacitors, biosensors, and electrodes for food monitoring as well as heart and respiration activity analysis, are realized. Biocompatibility tests on fruit-based cellulose reveal no shortcoming for on-skin applications. The employment of such natural and plastic-free substrate allows twofold strategies for electronics recycling. As a first approach, device dissolution is achieved at room temperature within 40 days, revealing transient behavior in natural solution and leaving no harmful residuals. Alternatively, the cellulose-based electronics is reintroduced in nature, as possible support for plant seeding and growth or even soil amendment. These results demonstrate the realization of green, low-cost and circular electronics, with possible applications in smart agriculture and the Internet-of-Thing, with no waste creation and zero or even positive impact on the ecosystem.
2023
- Permeable Thermistor Temperature Sensors Based on Porous Melamine Foam
[Articolo su rivista]
De Souza Oliveira, H.; Khaanghah, N. S.; Han, V. Y.; Carrasco-Pena, A.; Ion, A.; Haller, M.; Cantarella, G.; Munzenrieder, N.
abstract
Flexible sensors and electronics have gained much attention in recent years. They are especially interesting due to their abilities to conform to static and dynamic surfaces while keeping their functionality. These characteristics make them relevant for a wide range of applications, from health care and fitness monitoring to soft robotics. In this work, we go beyond simple mechanical flexibility and present a lightweight and permeable flexible sensor utilizing melamine foam as a substrate. The foam is coated with metallic copper (Cu) and semiconductive Indium-Gallium-Zinc-Oxide (InGaZnO) to form a thermistor-type temperature sensor. The sensor showed a very stable response when cycling the temperature between 25 °C and 51 °C, exhibiting a maximum sensitivity of -01.6°C-1, a permeability of 366.6m-2,h-1 at 24 °C, and a maximum resistance variation of -2.9%RH-1 when varying the relative humidity from 40% to 70%. The device also remained fully functional even after being bent to a radius of 5 mm.
2023
- Silicone/Carbon Black-Filled Elastomer-Based Self-Healing Strain Sensor
[Articolo su rivista]
Khaanghah, N. S.; Oliveira, H. D. S.; Riaz, R.; Catania, F.; Angeli, M. A. C.; Petti, L.; Cantarella, G.; Munzenrieder, N.
abstract
The recent interest in flexible and stretchable strain sensors reflects their potential applications in various fields, including healthcare monitoring, soft robotics, and electronic skins. In addition to high stretchability and excellent sensing properties, self-healability is also a highly desirable property of stretchable strain sensors as it allows increasing their lifespan and, thus, reduce electronic waste and cost. In this letter, a self-healing silicone tape is introduced as a self-healable flexible substrate that to fabricate a resistive strain sensor. The sensor has an average gauge factor of 34.6±0.26 up to 50% stretch. Moreover, the sensor can be cut and healed without the use of any adhesive materials or heating. After cutting, the healed sensor still has an average gauge factor of 2.0±0.006 up to 4% stretch, a stable response over 150 stretch-release cyclic tests, and breaks only after 18% of applied tensile strain.
2023
- Substrate-Free Transfer of Large-Area Ultra-Thin Electronics
[Articolo su rivista]
Oliveira, H. D. S.; Catania, F.; Lanthaler, A. H.; Carrasco-Pena, A.; Cantarella, G.; Munzenrieder, N.
abstract
Innovation in materials and technologies has promoted the fabrication of thin-film electronics on substrates previously considered incompatible because of their chemical or mechanical properties. Indeed, conventional fabrication processes, typically based on photolithography, involve solvents and acids that might harm fragile or exotic substrates. In this context, transfer techniques define a route to overcome the issues related to the nature of the substrate by using supportive carriers in the electronics stack that mitigate or avoid any damages during the fabrication process. Here, a substrate-free approach is presented for the transfer of ultra-thin electronics (<150nm-thick) where no additional layer besides the electronics one remains on the final substrate. Devices are transferred on several surfaces showing good adhesion and an average performance variation of 27%. Furthermore, a sensor bent to a radius of 15.25µm, shows variation in performance of 5%. The technique can also be sequentially repeated for the fabrication of stacked electronics, enabling the development of ultra-thin devices, compliant on unconventional surfaces.
2023
- Thin-Film Temperature Sensor on Flexible PEEK Fabric
[Relazione in Atti di Convegno]
Lanthaler, A. H.; Catania, F.; De Souza Oliveira, H.; Beltrami, C.; Carrasco-Pena, A.; Haller, M.; Munzenrieder, N.; Cantarella, G.
abstract
Plastic-based threads are widely and commonly used materials for the development of fabrics and textiles in a broad field of applications. Thanks to the properties of these materials, including mechanical flexibility, low weight, and breathability, it is possible to expand their functionality, through the integration with electronic devices, for sensing, actuation, or data transmission. In this work, a commercial fuel filtering fabric of Polyether ether ketone (PEEK) was used for the first time as a substrate for the fabrication of thin-film temperature sensors. The devices were tested and characterized over a temperature range from 20 °C to 60 °C (at a constant relative humidity of 30 %), showing a temperature coefficient resistance of 2 × 10-3-1. In addition, device functionality is demonstrated down to 27 mm bending radius, and in real-Time, while water vapor is blown through the fabric, with no performance variation. The development of these devices represents the first demonstration of thin-film temperature sensors directly fabricated on PEEK-based fabrics, paving the way for functionalized and smart membranes and threads, with possible applications in automotive, fuel, and gas filtering monitoring.
2023
- Unobtrusive Thin-Film Devices and Sustainable Green Electronics
[Relazione in Atti di Convegno]
Cantarella, G.; Catania, F.; Corsino, D.; Munzenrieder, N.
abstract
Over the last years, the research on unconventional electronics has paved the way to the realization of devices and systems with bespoke properties, including mechanical flexibility, optical transparency, and environmental sustainability. In this paper, alternative materials and novel fabrication methods to achieve highly-Transparent thin-film electronics and green, circular and sustainable devices are summarized. Firstly, the use of optically-Transparent materials, such as Indium-Tin-Oxide (ITO) and In-Ga-Zn-O (IGZO), has allowed the realization of imperceptible Thin-Film Transistors (TFTs), as well as ring oscillators, on flexible and stretchable substrates, for unobtrusive, flexible and low-power systems. Secondly, conductive traces are fabricated on recycled paper, acting as a green substrate, by using a CO2 laser for on-skin applications. Moreover, the employment of natural and recyclable materials allows device decomposition in natural solutions (i.e. lemon juice), as well as the use of our paper-based electronic as natural support for plant growth and seed germination in soil.
2022
- AC Performance of Flexible Transparent InGaZnO Thin-Film Transistors and Circuits
[Articolo su rivista]
Catania, F; Ahmad, M; Corsino, D; Saeedzadeh Khaanghah, N; Petti, L; Münzenrieder, N; Cantarella, G
abstract
2022
- Flexible Auxetic Structure as Substrates for Resistive Pressure Sensors
[Relazione in Atti di Convegno]
De Souza Oliveira, H.; Nijkoops, A.; Ciocca, M.; Carrasco-Pena, A.; Petti, L.; Cantarella, G.; Munzerieder, N.
abstract
The recent advances on flexible electronics and sensors have required the development of superior substrates that can withstand different levels and types of deformation, while keeping the integrity and functionality of the sensing materials. This work deals with the development of a zero Poisson's ratio (ZPR) auxetic structure integrated with a pressure sensing material. The ZPR structure can endure 15% of shearing deformation combined with 15% of stretch, presents a Poisson's ratio of 0.061 at a maximum longitudinal deformation of 76%. The resistive pressure sensing material presents a maximum sensitivity of (2.21x104 ± 3.59x103) MΩ/kg, an absolute resistance of around 20 MΩ, and a response time of 50 ms.
2022
- Flexible, Scalable and Buckled Electronics based on Oxide Thin-Film Transistors
[Relazione in Atti di Convegno]
Cantarella, G.; Catania, F.; Munzenrieder, N.; Petti, L.
abstract
2022
- Flexible Thin-Film Temperature Sensors on Upcycled Polyethylene Terephthalate (PET) Substrates for the Circularity of Economy
[Relazione in Atti di Convegno]
Carrasco-Pena, A.; Catania, F.; Cantarella, G.; Haller, M.; Nippa, M.; Munzenrieder, N.
abstract
The use of plastics for daily life applications keeps rising rapidly making these polymers a material of choice in many fields, including electronics. Nevertheless, the pollution generated from the fabrication, usage and disposal of plastics has become an environmental problem that is impacting most of the ecosystems in our planet. Efforts are being made to reduce the impact plastics have in nature, with recycling and upcycling as promising approaches that not only reduce the harm plastics to the biosphere, but also help in developing a circular model for the usage of these organic polymers. In this work, polyethylene terephthalate (PET) was recycled from commercial beverage bottles to create a sustainable substrate for the fabrication of thin-film electronics. As an application for the substrate, temperature sensors were developed and their response was analyzed over a temperature range from 5 °C to 65 °C with a temperature coefficient resistance (α) = 0.002 °C-1, used to measure the temperature of commercial bottle beverages. The development of these substrates provides a second life to the PET from bottles, paving the way for the sustainable and circular usage of plastic as substrates for thin-film electronic devices and a reduction of the negative effects their presence and footprint have in nature.
2022
- Laser-Induced Graphene Electrodes Modified with a Molecularly Imprinted Polymer for Detection of Tetracycline in Milk and Meat
[Articolo su rivista]
Abera, Bd; Ortiz-Gómez, I; Shkodra, B; Romero, Fj; Cantarella, G; Petti, L; Salinas-Castillo, A; Lugli, P; Rivadeneyra, A
abstract
2022
- Monolithic Integration, Performance, and Comparison of Self-Aligned and Conventional IGZO Thin-Film Transistors on a Flexible Substrate
[Articolo su rivista]
Corsino, Dianne; Catania, Federica; Ishida, Koichi; Meister, Tilo; Ellinger, Frank; Cantarella, Giuseppe; Münzenrieder, Niko
abstract
Flexible electronics, most prominently thin-film
transistors (TFTs) on plastic substrates, are considered the prime
building block for the realization of innovative wearable systems.
Two of the currently most successful fabrication processes of
transistors on free-standing polymer foils are large-areacompatible devices structured by conventional UV lithography
and high-speed transistors realized by self-alignment. Here, both
processes, based on InGaZnO (IGZO) technology, are combined
for the first time. This not only demonstrates their compatibility,
but also showcases the differences between the resulting devices.
Concerning the geometry, TFTs with the same nominal designed
channel length of 1.5 µm exhibit a real channel length of
1.5 µm (self-aligned) and 4.5 µm (conventional). Furthermore,
the integrated side-by-side fabrication enables the electrical
comparison of both types of TFTs excluding external factors.
While all TFTs exhibit similar threshold voltages around 0 V
and excellent on/off ratios of ≈1010, conventional TFTs are
easier to fabricate and have comparably higher mobilities up to
16 cm2V−1s−1. At the same time, self-aligned TFTs demonstrate
better ac performance, demonstrating a maximum oscillation
frequency of 216 MHz. This integration shows new possibilities
for the realization of complex systems made from building
blocks optimized for reliability and speed
2022
- Smart Approach for the Design of Highly Selective Aptamer-Based Biosensors
[Articolo su rivista]
Douaki, Ali; Garoli, Denis; Inam, A K M Sarwar; Angeli, Martina Aurora Costa; Cantarella, Giuseppe; Rocchia, Walter; Wang, Jiahai; Petti, Luisa; Lugli, Paolo
abstract
Aptamers are chemically synthesized single-stranded DNA or RNA oligonucleotides widely used nowadays in sensors and nanoscale devices as highly sensitive biorecognition elements. With proper design, aptamers are able to bind to a specific target molecule with high selectivity. To date, the systematic evolution of ligands by exponential enrichment (SELEX) process is employed to isolate aptamers. Nevertheless, this method requires complex and time-consuming procedures. In silico methods comprising machine learning models have been recently proposed to reduce the time and cost of aptamer design. In this work, we present a new in silico approach allowing the generation of highly sensitive and selective RNA aptamers towards a specific target, here represented by ammonium dissolved in water. By using machine learning and bioinformatics tools, a rational design of aptamers is demonstrated. This "smart" SELEX method is experimentally proved by choosing the best five aptamer candidates obtained from the design process and applying them as functional elements in an electrochemical sensor to detect, as the target molecule, ammonium at different concentrations. We observed that the use of five different aptamers leads to a significant difference in the sensor's response. This can be explained by considering the aptamers' conformational change due to their interaction with the target molecule. We studied these conformational changes using a molecular dynamics simulation and suggested a possible explanation of the experimental observations. Finally, electrochemical measurements exposing the same sensors to different molecules were used to confirm the high selectivity of the designed aptamers. The proposed in silico SELEX approach can potentially reduce the cost and the time needed to identify the aptamers and potentially be applied to any target molecule.
2022
- Thin-film Electronics on Active Substrates: Review of Materials, Technologies, and Applications
[Articolo su rivista]
Catania, F; De Souza Oliveira, H; Lugoda, P; Cantarella, G; Münzenrieder, N
abstract
2022
- 3D bio-printed light-sensitive cell scaffolds based on polymer nanoparticles for bio-photonics applications
[Relazione in Atti di Convegno]
Ciocca, M.; Febo, C.; Massoumi, F.; Altana, A.; Cantarella, G.; Lugli, P.; Petti, L.
abstract
Biotechnology has been rapidly growing in recent years with unprecedent achievements in regenerative medicine and tissue engineering. 3D bio-printing is one of the latest technologies used to develop complex structures mimicking organs and tissues, as well as functional 3D cell scaffolds. Engineered cell scaffolds supplemented with organic materials can be used as bio-electronic interfaces and biomedical sensing. In this work, a novel 3D bioprinted cell scaffold enhanced with light-responsive organic semiconducting polymer nanoparticles is presented. The lightsensitive cell scaffold can be used for light control and modulation of cellular activities with several applications in neural engineering and regenerative medicine.
2021
- Aluminum Oxide as a Dielectric and Passivation Layer for (flexible) Metal-Oxide and 2D Semiconductor Devices
[Relazione in Atti di Convegno]
Daus, A.; Mcclellan, C. J.; Schauble, K.; Costa, J. C.; Grady, R. W.; Petti, L.; Cantarella, G.; Mnzenrieder, N.; Pop, E.
abstract
We discuss the role of aluminum oxide (i.e. Al2O3 when stoichiometric) for transistors and sensors based on oxide semiconductors such as InGaZnO (IGZO) and two-dimensional (2D) semiconductors, such as monolayer MoS2. Aluminum oxide is a well-known capping and dielectric layer in semiconductor technology typically deposited by atomic-layer deposition (ALD), which offers a dense and high-quality film with low gas permeability even when deposited on flexible substrates. However, when deposited at low temperature (< 200C), aluminum oxide can include a significant amount of fixed charges and defects, which lead to unusual charge trapping and doping effects in semiconductor devices. For example, such charge trapping can cause (apparent) sub-60 mV/decade subthreshold swing at room temperature in IGZO transistors, but can also lead to potential applications in neuromorphic computing. We also discuss effective doping (-1013 cm-2) of 2D semiconductors by thin ALD-grown non-stoichiometric AlOx capping layers. This is achieved with an aluminum seed layer, which enables uniform growth of the subsequently deposited ALD film. This approach leads to a negative shift in threshold voltage, record on-state current (-700 μA/μm) in a monolayer semiconductor, and drastic reduction in contact resistance. Finally, we investigate the passivation effects of Al2O3 capping, which limits the interaction of the underlying semiconductors with ambient air and moisture. We demonstrate improved response in MoS2temperature sensors and long-term stability in flexible MoS2transistors (8 months). Further, we evaluate the effects of Al2O3 passivation on IGZO transistors after aging for 80 months.
2021
- Bendable metal oxide thin-film transistors and circuits for analog electronics applications
[Relazione in Atti di Convegno]
Petti, L; Cantarella, G; Costa, Jc; Münzenrieder, N
abstract
2021
- Cost-effective, mask-less, and high-throughput prototyping of flexible hybrid electronic devices using dispense printing and conductive silver ink
[Relazione in Atti di Convegno]
Sahira, Vasquez; Mattia, Petrelli; Martina Costa, Angeli; Julio, Costa; Enrico, Avancini; Cantarella, G; Niko, Münzenrieder; Paolo, Lugli; Luisa, Petti
abstract
2021
- Design and Fabrication of a Pillar-based Piezoelectric Microphone exploiting 3D-Printing Technology
[Articolo su rivista]
Ricci, Y.; Sorrentino, A.; La Torraca, P.; Cattani, L.; Cotogno, M.; Cantarella, G.; Orazi, L.; Castagnetti, D.; Lugli, P.; Larcher, L.
abstract
This letter presents a 3-D-printed piezoelectric microphone with enhanced voltage sensitivity. The sensitivity is
improved by a combination of a single-pillar mechanical design and a specific polyvinylidene fluoride (PVDF)-film electrode
patterning. The moving part of the mechanical structure and the chassis are 3D-printed as a single unit and trimmed
by laser cutting, allowing for a simple fabrication of the device. The measured sensitivity of 1 mV/Pa (±6 dB) in the
bandwidth 500–2500 Hz agrees with simulations, showing an improvement over similar pillar-based piezoelectric sensor
solutions. The sensitivity performance is shown to be comparable to existing microphones with different technologies. The
microphone is also characterized by excellent linearity within the measurable range. 3D-printing technique can thus be
adopted for the manufacturing of low cost and highly customizable microphone sensors.
2021
- Design and Validation of a Portable AD5933–Based Impedance Analyzer for Smart Agriculture
[Articolo su rivista]
Ibba, P; Crepaldi, M; Cantarella, G; Zini, G; Barcellona, A; Rivola, M; Petrelli, M; Petti, L; Lugli, P
abstract
2021
- Mechanical and Electrical Design Strategies for Flexible InGaZnO Circuits
[Relazione in Atti di Convegno]
Cantarella, G; Münzenrieder, N; Petti, L; Ishida, K; Meister, T; Carta, C; Ellinger, F; Hopf, R
abstract
2021
- Oxide Thin-Film Electronics for the Front-End Conditioning of Flexible Magnetic Field Sensors
[Relazione in Atti di Convegno]
Niko, Münzenrieder; Cantarella, G; Luisa, Petti; Júlio, Costa
abstract
2021
- Recycled Carbon-based Strain Sensors: An Ecofriendly Approach using Char and Coconut Oil
[Relazione in Atti di Convegno]
de Souza Oliveira, H.; Catania, F.; Cantarella, G.; Benedetti, V.; Baratieri, M.; Munzenrieder, N.
abstract
Bio-compatible high stretchable strain sensors can be applied in several areas ranging from engineering to medicine. Among many efforts in developing new sensors, there is a growing demand for eco-friendly devices characterized by a minimum environmental impact and a low cost. This work deals with the development and analysis of a biocompatible, eco-friendly, and unexpensive strain sensor, easily manufacturable, consisting of natural coconut oil, and recycled char, the solid residue obtained after the gasification of biomass. The results demonstrate an average gauge factor of (23.2 ± 2.5), with a linear response until 80% strain, a higher hysteresis occurring between strain values of 25% 40% and a stable and reliable response after 250 stretch/release cycles.
2021
- Supervised binary classification methods for strawberry ripeness discrimination from bioimpedance data
[Articolo su rivista]
Ibba, P.; Tronstad, C.; Moscetti, R.; Mimmo, T.; Cantarella, G.; Petti, L.; Martinsen, O. G.; Cesco, S.; Lugli, P.
abstract
Strawberry is one of the most popular fruits in the market. To meet the demanding consumer and market quality standards, there is a strong need for an on-site, accurate and reliable grading system during the whole harvesting process. In this work, a total of 923 strawberry fruit were measured directly on-plant at different ripening stages by means of bioimpedance data, collected at frequencies between 20 Hz and 300 kHz. The fruit batch was then splitted in 2 classes (i.e. ripe and unripe) based on surface color data. Starting from these data, six of the most commonly used supervised machine learning classification techniques, i.e. Logistic Regression (LR), Binary Decision Trees (DT), Naive Bayes Classifiers (NBC), K-Nearest Neighbors (KNN), Support Vector Machine (SVM) and Multi-Layer Perceptron Networks (MLP), were employed, optimized, tested and compared in view of their performance in predicting the strawberry fruit ripening stage. Such models were trained to develop a complete feature selection and optimization pipeline, not yet available for bioimpedance data analysis of fruit. The classification results highlighted that, among all the tested methods, MLP networks had the best performances on the test set, with 0.72, 0.82 and 0.73 for the F1, F0.5 and F2-score, respectively, and improved the training results, showing good generalization capability, adapting well to new, previously unseen data. Consequently, the MLP models, trained with bioimpedance data, are a promising alternative for real-time estimation of strawberry ripeness directly on-field, which could be a potential application technique for evaluating the harvesting time management for farmers and producers.
2021
- Thermal Stability of Flexible IGZO/Ag Schottky Diodes on Cellulose Microfiber Paper Substrate
[Relazione in Atti di Convegno]
Vasquez Baez, Sc; Ahmad, M; Petrelli, M; Costa Angeli, Ma; Riaz, R; Douaki, A; Cantarella, G; Münzenrieder, N; Lugli, P; Petti, L
abstract
2021
- 2.4 GHz Microstrip Patch Antenna Fabricated by Means of Laser Induced Graphitization of a Cellulose-based Paper Substrate
[Relazione in Atti di Convegno]
Ahmad, Mukhtar; Cantarella, Giuseppe; Angeli, Martina Aurora Costa; Madagalam, Mallikarjun; Ebner, Christian; Ciocca, Manuela; Riaz, Raheel; Ibba, Pietro; Petrelli, Mattia; Merino, Ignacio; Cohen, Nitzan; Lugli, Paolo; Petti, Luisa
abstract
2020
- A PEDOT: PSS/SWCNT-Coated Screen Printed Immunosensor for Histamine Detection in Food Samples
[Relazione in Atti di Convegno]
Bajramshahe, Shkodra; Ali, Douaki; Biresaw, D Abera; Pietro, Ibba; Enrico, Avancini; Cantarella, G; Luisa, Petti; Paolo, Lugli
abstract
2020
- Bio-impedance and circuit parameters: An analysis for tracking fruit ripening
[Articolo su rivista]
Ibba, P; Falco, A; Abera, B; Cantarella, G; Petti, L; Lugli, P
abstract
The evaluation of fruit quality from the field to the table, through its storage, handling and transport has become of paramount importance to meet production and consumers demands. For this purpose, fast, reliable and low-cost non-destructive techniques are highly desirable, to avoid food waste and allow a real-time decision making. Among non-destructive techniques, Electrical Impedance Spectroscopy (EIS) has shown great potential due to the possibility to correlate the physio-chemical evolution of the fruit to changes of electrical parameters. In this paper, the effect of ageing on apples and bananas during 13 d at room temperature was studied using a microcontroller-based EIS system, in a frequency range from 100 Hz to 85 kHz. The bio-impedance changes were evaluated over time and the influence of the applied frequencies on its variation was investigated. Data were fitted with a proposed equivalent circuit, modelling both the interaction between the fruit and the sensor and the flow of current in the samples tissues. To validate the results, the circuit parameter changes were physiologically explained and the fitting compared with models found in literature. The results highlighted the potential of this non-destructive technique for monitoring the ripening and senescence of fruit, obtaining a good correlation of the impedance evolution with the low frequency points. The model fitting resulted in a Root Mean Squared Error (RMSE), for apples (376.5 Ω - 2.66%) and bananas (110.8 Ω - 2.82%), was comparable or better than best literature models. Finally, changes of circuit component values over time was explained for the electrode-fruit interaction and for the current flow in the plant tissues, giving a better insight of fruit ripening and senescence.
2020
- Flexible and Printed Electrochemical Immunosensor Coated with Oxygen Plasma Treated SWCNTs for Histamine Detection
[Articolo su rivista]
Shkodra, B; Abera, Bd; Cantarella, G; Douaki, A; Avancini, E; Petti, L; Lugli, P
abstract
2020
- Flexible Screen Printed Aptasensor for Rapid Detection of Furaneol: A Comparison of CNTs and AgNPs Effect on Aptasensor Performance
[Articolo su rivista]
Douaki, A; Abera, Bd; Cantarella, G; Shkodra, B; Mushtaq, A; Ibba, P; Inam, Akms; Petti, L; Lugli, P
abstract
2020
- Focused ion beam milling for the fabrication of 160 nm channel length IGZO TFTs on flexible polymer substrates
[Articolo su rivista]
Münzenrieder, N; Shorubalko, I; Petti, L; Cantarella, G; Shkodra, B; Meister, T; Ishida, K; Carta, C; Ellinger, F; Tröster, G
abstract
2020
- FruitMeter: An AD5933-Based Portable Impedance Analyzer for Fruit Quality Characterization
[Relazione in Atti di Convegno]
Pietro, Ibba; Marco, Crepaldi; Cantarella, G; Giorgio, Zini; Alessandro, Barcellona; Mattia, Petrelli; Biresaw, D Abera; Bajramshahe, Shkodra; Luisa, Petti; Paolo, Lugli
abstract
2020
- Long-Term Aging of Al2O3Passivated and Unpassivated Flexible a-IGZO TFTs
[Articolo su rivista]
Costa, Jc; Kermani, ; Cantarella, Giuseppe; Cantarella, G; Petti, L; Vogt, C; Daus, A; Knobelspies, S; Troster, G; Munzenrieder, Ns
abstract
2020
- Review of recent trends in flexible metal oxide thin-film transistors for analog applications
[Articolo su rivista]
Cantarella, G; Costa, J; Meister, T; Ishida, K; Carta, C; Ellinger, F; Lugli, P; Munzenrieder, N; Petti, L
abstract
Thanks to the extraordinary advances flexible electronics have experienced over the last decades, applications such as conformable active-matrix displays, ubiquitously integrated disposable flexible sensor nodes, wearable or textile-integrated systems, as well as imperceptible and transient implants are now reachable. To enable these applications, specialized analog circuits able to transmit and receive data, condition sensors' parameters, drive actuators or control powering devices are required. High-performance sensor conditioning, driving and transceiver circuits on a wide range of flexible substrates are therefore extremely important to develop. However, the currently available materials and processes compatible with mechanically flexible substrates impose massive limitations in terms of large-area uniformity, device dimensions' shrinkability and circuit design, challenging the realization of flexible analog systems. Among state-of-the-art technologies employing low-temperature fabrication processes, thin-film transistors (TFTs) based on metal oxide semiconductors represent the potentially best compromise in terms of prize, performance, technology maturity and capacity to realize complex systems. This is why metal oxide TFTs are nowadays widely used for flexible, light-weight, transparent, stretchable and bio-degradable analog circuits and systems. Here, we review the current trends of flexible metal oxide TFTs for analog applications. First, an introduction is given, where current challenges and requirements related to the realization of flexible analog circuits and systems are analysed. Additionally, TFT performance parameters and configurations are briefly revised. Then, the recent advances in the field of flexible metal oxide TFTs for analog applications are summarized. In particular, all reported approaches to reduce the channel length and improve the AC performance are shown. Next, the current state of flexible metal oxide TFT-based analog circuits is shown, discussing n-type only and complementary circuit configurations. The last topic of the review covers systems based on flexible metal oxide analog circuits. Finally, a conclusion is drawn and an outlook over the field is provided.
2020
- Selection of Cole model Bio-impedance parameters for the estimation of the ageing evolution of apples
[Relazione in Atti di Convegno]
Pietro, Ibba; Biresaw Demelash, Abera; Cantarella, G; Aniello, Falco; Luisa, Petti; Paolo, Lugli
abstract
2020
- Single-Walled Carbon Nanotube-Coated Flexible and Soft Screen-Printed Electrochemical Biosensor for Ochratoxin a Detection
[Relazione in Atti di Convegno]
Biresaw Demelash, Abera; Bajramshahe, Shkodra; Ali, Douaki; Pietro, Ibba; Cantarella, G; Luisa, Petti; Paolo, Lugli
abstract
2019
- Design of bendable high-frequency circuits based on short-channel InGaZnO TFTs
[Relazione in Atti di Convegno]
Münzenrieder, N; Costa, J; Petti, L; Cantarella, G; Meister, T; Ishida, K; Carta, C; Ellinger, F
abstract
2019
- Development of Flexible Dispense-Printed Electrochemical Immunosensor for Aflatoxin M1 Detection in Milk
[Articolo su rivista]
Abera Demelash, B; Falco, A; Ibba, P; Cantarella, G; Petti, L; Lugli, P
abstract
2019
- Fabrication and AC Performance of Flexible Indium-Gallium-Zinc-Oxide Thin-Film Transistors
[Articolo su rivista]
Münzenrieder, N; Cantarella, G; Petti, L
abstract
2019
- Flexible Dispense-Printed Electrochemical Biosensor for Aflatoxin M1 Detection Employing NaOH and Oxygen Plasma Electrode Pre-treatment
[Relazione in Atti di Convegno]
Abera, B; Falco, A; Ibba, P; Cantarella, G; Petti, L; Lugli, P
abstract
In this work, flexible dispense-printed biosensors for AFM1 detection in milk were fabricated on polyethylene terephthalate (PET) substrate employing sodium hydroxide (NaOH) bath and oxygen plasma (OP) pre-treatment. Thanks to the use of dispense-printed silver and silver/silver chloride electrodes, our flexible biosensors are able to detect a minimum AFM1 concentration of 0.010 μg/L, which is to the best of our knowledge the the best lower level of detection ever reported for AFM1 sensors. Even if sensors with untreated and treated electrodes yield the same sensitivity, NaOH bath and OP pre-treatments result in a reduction of the electrode resistance by 46%, and 21.6%, respectively. These results prove that pre-treatment is a useful technique to modify the electrical and surface properties of the dispense-printed electrodes, by removing binder polymers and impurities of the employed ink paste. Bendability tests showed a maintaned fuctionality even after 1000 bending cycles down to 9 mm radius with variations below 11%.
2019
- Flexible Green Perovskite Light Emitting Diodes
[Articolo su rivista]
Cantarella, G; Kumar, S; Vogt, C; Knobelspies, S; Takabayashi, A; Jagielski, J; Münzenrieder, N; Daus, A; Petti, L; Salvatore, Ga; Lugli, P; Shih, C; Troster, G
abstract
2019
- 5-31-Hz 188-μW Light-Sensing Oscillator With Two Active Inductors Fully Integrated on Plastic
[Articolo su rivista]
Meister, T; Ishida, K; Knobelspies, S; Cantarella, G; Münzenrieder, N; Troster, G; Carta, C; Ellinger, F
abstract
2018
- Bendable Printed and Thin-film Electronics for Wireless Communications
[Relazione in Atti di Convegno]
Ellinger, F; Ishida, K; Meister, T; Boroujeni, Bk; Barahona, M; Carta, C; Münzenrieder, N; Cantarella, G; Petti, L; Knobelspies, S; Salvatore, Ga; Tröster, G; Schmidt, Gc; Hübler, Ac
abstract
2018
- Design of Engineered Elastomeric Substrate for Stretchable Active Devices and Sensors
[Articolo su rivista]
Cantarella, G; Costanza, V; Ferrero, A; Hopf, R; Vogt, C; Varga, M; Petti, L; Münzenrieder, N; Buthe, L; Salvatore, G; Claville, A; Bonanomi, L; Daus, A; Knobelspies, S; Daraio, C; Troster, G
abstract
In the field of flexible electronics, emerging applications require biocompatible and unobtrusive devices, which can withstand different modes of mechanical deformation and achieve low complexity in the fabrication process. Here, the fabrication of a mesa-shaped elastomeric substrate, supporting thin-film transistors (TFTs) and logic circuits (inverters), is reported. High-relief structures are designed to minimize the strain experienced by the electronics, which are fabricated directly on the pillars' surface. In this design configuration, devices based on amorphous indium-gallium-zinc-oxide can withstand different modes of deformation. Bending, stretching, and twisting experiments up to 6 mm radius, 20% uniaxial strain, and 180 degrees global twisting, respectively, are performed to show stable electrical performance of the TFTs. Similarly, a fully integrated digital inverter is tested while stretched up to 20% elongation. As a proof of the versatility of mesa-shaped geometry, a biocompatible and stretchable sensor for temperature mapping is also realized. Using pectin, which is a temperature-sensitive material present in plant cells, the response of the sensor shows current modulation from 13 to 28 degrees C and functionality up to 15% strain. These results demonstrate the performance of highly flexible electronics for a broad variety of applications, including smart skin and health monitoring.
2018
- Effects of stair case gate bias stress in IGZO/Al2O3 flexible TFTs
[Articolo su rivista]
Buonomo, M; Wrachien, N; Lago, N; Cantarella, G; Cester, A
abstract
2018
- Flexible CMOS electronics based on p-type Ge2Sb2Te5 and n-type InGaZnO4 semiconductors
[Relazione in Atti di Convegno]
Daus, A.; Han, S.; Knobelspies, S.; Cantarella, G.; Vogt, C.; Munzenrieder, N.; Troster, G.
abstract
Ultra-thin p-type chalcogenide glass Ge2Sb2Te5 (GST) semiconductor layers are employed to form flexible thin-film transistors (TFTs). For the first time, TFTs based on GST show saturating output characteristics and an ON/OFF ratio up to 388, exceeding present reports by a factor of ∼20. The channel current modulation is greatly enhanced by using ultra-thin 5 nm thick amorphous GST layers and 20 nm thick high-k Al2O3 gate dielectrics. Flexible CMOS circuits are realized in combination with the n-type oxide semiconductor InGaZnO4 (IGZO). The CMOS inverters show voltage gain of up to 69. Furthermore, flexible NAND gates are presented. The bending stability is shown for a tensile radius of 6 mm. U.S. Government work not protected by U.S.
2018
- Flexible InGaZnO TFTs With f(max) Above 300 MHz
[Articolo su rivista]
Münzenrieder, N; Ishida, K; Meister, T; Cantarella, G; Petti, L; Carta, C; Ellinger, F; Troster, G
abstract
In this letter, the AC performance and influence of bending on flexible IGZO thin-film transistors, exhibiting a maximum oscillation frequency (maximum power gain frequency) f(max) beyond 300 MHz, are presented. Self-alignment was used to realize TFTs with channel length down to 0.5 mu m. The layout of these TFTs was optimized for good AC performance. Besides the channel dimensions, this includes ground-signal-ground contact pads. The AC performance of these short channel devices was evaluated by measuring their two port scattering parameters. These measurements were used to extract the unity gain power frequency from the maximum stable gain and the unilateral gain. The two complimentary definitions result in f max values of (304 +/- 12) and (398 +/- 53) MHz, respectively. Furthermore, the transistor performance is not significantly altered by mechanical strain. Here, f(max) reduces by 3.6% when a TFT is bent to a tensile radius of 3.5 mm.
2018
- Flexible In-Ga-Zn-O Thin-Film Transistors With Sub-300-nm Channel Lengths Defined by Two-Photon Direct Laser Writing
[Articolo su rivista]
Petti, L; Greco, E; Cantarella, G; Münzenrieder, N; Vogt, C; Troster, G
abstract
2018
- Ge2Sb2Te5 p-Type Thin-Film Transistors on Flexible Plastic Foil
[Articolo su rivista]
Daus, A; Han, S; Knobelspies, S; Cantarella, G; Tröster, G
abstract
In this work, we show the performance improvement of p-type thin-film transistors (TFTs) with Ge2Sb2Te5 (GST) semiconductor layers on flexible polyimide substrates, achieved by downscaling of the GST thickness. Prior works on GST TFTs have typically shown poor current modulation capabilities with ON/OFF ratios ≤20 and non-saturating output characteristics. By reducing the GST thickness to 5 nm, we achieve ON/OFF ratios up to ≈300 and a channel pinch-off leading to drain current saturation. We compare the GST TFTs in their amorphous (as deposited) state and in their crystalline (annealed at 200 °C) state. The highest effective field-effect mobility of 6.7 cm2/Vs is achieved for 10-nm-thick crystalline GST TFTs, which have an ON/OFF ratio of ≈16. The highest effective field-effect mobility in amorphous GST TFTs is 0.04 cm2/Vs, which is obtained in devices with a GST thickness of 5 nm. The devices remain fully operational upon bending to a radius of 6 mm. Furthermore, we find that the TFTs with amorphous channels are more sensitive to bias stress than the ones with crystallized channels. These results show that GST semiconductors are compatible with flexible electronics technology, where high-performance p-type TFTs are strongly needed for the realization of hybrid complementary metal-oxide-semiconductor (CMOS) technology in conjunction with popular n-type oxide semiconductor materials.
2018
- Improvement of contact resistance in flexible a-IGZO thin-film transistors by CF4/O-2 plasma treatment
[Articolo su rivista]
Knobelspies, S; Takabayashi, A; Daus, A; Cantarella, G; Münzenrieder, N; Troster, G
abstract
In this work, we analyze the effect of CF4/O-2 plasma treatment on the contact interface between the amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) semiconductor and Titanium-Gold electrodes. First, the influence of CF4/O-2 plasma treatment is evaluated using transmission line structures and compared to pure O-2 and CF4 plasma, resulting in a reduction of the contact resistance RC by a factor of 24.2 compared to untreated interfaces. Subsequently, the CF4/O-2 plasma treatment is integrated in the a-IGZO thin-film transistor (TFT) fabrication process flow. We achieve a reduction of the gate bias dependent RC by a factor up to 13.4, which results in an increased current drive capability. Combined with an associated channel length reduction, the effective linear field-effect mobility mu(lin,FE,eff) is increased by up to 74.6% for the CF4/O-2 plasma treated TFTs compared to untreated reference devices.
2018
- Metal-Halide Perovskites for Gate Dielectrics in Field-Effect Transistors and Photodetectors Enabled by PMMA Lift-Off Process
[Articolo su rivista]
Daus, A.; Roldan-Carmona, C.; Domanski, K.; Knobelspies, S.; Cantarella, G.; Vogt, C.; Gratzel, M.; Nazeeruddin, M. K.; Troster, G.
abstract
Metal-halide perovskites have emerged as promising materials for optoelectronics applications, such as photovoltaics, light-emitting diodes, and photodetectors due to their excellent photoconversion efficiencies. However, their instability in aqueous solutions and most organic solvents has complicated their micropatterning procedures, which are needed for dense device integration, for example, in displays or cameras. In this work, a lift-off process based on poly(methyl methacrylate) and deep ultraviolet lithography on flexible plastic foils is presented. This technique comprises simultaneous patterning of the metal-halide perovskite with a top electrode, which results in microscale vertical device architectures with high spatial resolution and alignment properties. Hence, thin-film transistors (TFTs) with methyl-ammonium lead iodide (MAPbI3) gate dielectrics are demonstrated for the first time. The giant dielectric constant of MAPbI3 (>1000) leads to excellent low-voltage TFT switching capabilities with subthreshold swings ≈80 mV decade−1 over ≈5 orders of drain current magnitude. Furthermore, vertically stacked low-power Au-MAPbI3-Au photodetectors with close-to-ideal linear response (R2 = 0.9997) are created. The mechanical stability down to a tensile radius of 6 mm is demonstrated for the TFTs and photodetectors, simultaneously realized on the same flexible plastic substrate. These results open the way for flexible low-power integrated (opto-)electronic systems based on metal-halide perovskites.
2018
- N-type to p-type transition upon phase change in Ge6Sb1Te2 compounds
[Articolo su rivista]
Daus, A; Knobelspies, S; Cantarella, G; Tröster, G
abstract
In this work, we study the electronic properties of Ge6Sb1Te2 compounds in thin-film transistor architectures on plastic substrates, which enable the extraction of field-effect mobility μFE, carrier density, and polarity in highly resistive thin-films. We find that the Ge-rich compound exhibits n-type conductivity in the amorphous phase with a gradual transition to p-type behavior upon thermal annealing. At a temperature of 350 °C, the material undergoes a phase change, which is confirmed by x-ray diffraction measurements. After the phase change, μFE and the conductivity increase and the polarity becomes p-type, while the carrier density does not change significantly. Furthermore, we compare the properties of Ge6Sb1Te2 to the commonly studied material composition of Ge2Sb2Te5 in the Hall measurement and find that the carrier density of the Ge-rich compound is reduced by 2 orders of magnitude, which indicates that the significantly lower concentration of Ge vacancies leads to a reduction of p-type doping.
2018
- Photo-Induced Room-Temperature Gas Sensing with a-IGZO Based Thin-Film Transistors Fabricated on Flexible Plastic Foil
[Articolo su rivista]
Knobelspies, S; Bierer, B; Daus, A; Takabayashi, A; Salvatore, G; Cantarella, G; Perez, A; Wöllenstein, J; Palzer, S; Tröster, G
abstract
We present a gas sensitive thin-film transistor (TFT) based on an amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) semiconductor as the sensing layer, which is fabricated on a free-standing flexible polyimide foil. The photo-induced sensor response to NO2 gas at room temperature and the cross-sensitivity to humidity are investigated. We combine the advantages of a transistor based sensor with flexible electronics technology to demonstrate the first flexible a-IGZO based gas sensitive TFT. Since flexible plastic substrates prohibit the use of high operating temperatures, the charge generation is promoted with the help of UV-light absorption, which ultimately triggers the reversible chemical reaction with the trace gas. Furthermore, the device fabrication process flow can be directly implemented in standard TFT technology, allowing for the parallel integration of the sensor and analog or logical circuits.
2018
- Simple and accurate single transistor technique for parameters extraction from organic and inorganic thin film devices
[Articolo su rivista]
Buonomo, M; Lago, N; Cantarella, G; Wrachien, N; Natali, M; Prescimone, F; Benvenuti, E; Muccini, M; Toffanin, S; Cester, A
abstract
In this work, a new simple and easy to use technique for parameter extraction in thin film transistors is presented and discussed. To avoid the approximations needed to extract the parameters from the linear regime, our method operates in the saturation regime allowing for the correct determination of all the transistor parameters, including its parasitic resistances and the mobility enhancement factor. To prove the efficacy of the presented technique, we extrapolated the parameters from simulated transistors with increasing parasitic resistances, showing that the presented method allows a much better estimation of the transistors parameters with respect to standard extrapolation techniques. Finally, we experimentally validate our procedure by performing a complete characterization of both organic and inorganic transistors featuring dihexyl-quaterthiophene and indium-gallium-zinc-oxide as semiconducting materials, respectively.
2017
- Biodegradable and Highly Deformable Temperature Sensors for the Internet of Things
[Articolo su rivista]
Magno, M; Hopf, R; Tröster, G; Salvatore, G; Sülzle, J; Dalla Valle, F; Cantarella, G; Robotti, F; Jokic, P; Knobelspies, S; Daus, A; Büthe, L; Petti, L; Kirchgessner, N
abstract
Recent advances in biomaterials, thin film processing, and nanofabrication offer the opportunity to design electronics with novel and unique capabilities, including high mechanical stability and biodegradation, which are relevant in medical implants, environmental sensors, and wearable and disposable devices. Combining reliable electrical performance with high mechanical deformation and chemical degradation remains still challenging. This work reports temperature sensors whose material composition enables full biodegradation while the layout and ultrathin format ensure a response time of 10 ms and stable operation demonstrated by a resistance variation of less than 0.7% when the devices are crumpled, folded, and stretched up to 10%. Magnesium microstructures are encapsulated by a compostable-certified flexible polymer which exhibits small swelling rate and a Young's modulus of about 500 MPa which approximates that of muscles and cartilage. The extension of the design from a single sensor to an array and its integration onto a fluidic device, made of the same polymer, provides routes for a smart biodegradable system for flow mapping. Proper packaging of the sensors tunes the dissolution dynamics to a few days in water while the connection to a Bluetooth module demonstrates wireless operation with 200 mK resolution prospecting application in food tracking and in medical postsurgery monitoring.
2017
- Buckled Thin-Film Transistors and Circuits on Soft Elastomers for Stretchable Electronics
[Articolo su rivista]
Cantarella, G; Vogt, C; Hopf, R; Münzenrieder, N; Andrianakis, P; Petti, L; Daus, A; Knobelspies, S; Büthe, L; Tröster, G; Salvatore, G
abstract
2017
- Campanile Near-Field Probes Fabricated by Nanoimprint Lithography on the Facet of an Optical Fiber
[Articolo su rivista]
Calafiore, G; Koshelev, A; Darlington, T; Borys, N; Melli, M; Polyakov, A; Cantarella, G; Allen, F; Lum, P; Wong, E; Sassolini, S; Weber-Bargioni, A; Schuck, P; Cabrini, S; Munechika, K
abstract
2017
- Charge Trapping Mechanism Leading to Sub-60-mV/decade-Swing FETs
[Articolo su rivista]
Daus, A; Vogt, C; Münzenrieder, N; Petti, L; Knobelspies, S; Cantarella, G; Luisier, M; Salvatore, Ga; Troster, G
abstract
In this paper, we present a novel method to reduce the subthreshold swing (SS) of FETs below 60 mV/decade. Through modeling, we directly relate trap charge movement between the gate electrode and the gate dielectric to SS reduction. We experimentally investigate the impact of charge exchange between a Cu gate electrode and a 5-nm-thick amorphous Al2O3 gate dielectric in an InGaZnO4 thin-film transistor. Positive trap charges are generated inside the gate dielectric while the semiconductor is in accumulation. During the subsequent detrapping, the SS diminishes to a minimum value of 46 mV/decade at room temperature. Furthermore, we relate the charge trapping/detrapping effects to a negative capacitance behavior of the Cu/Al2O3 metal-insulator structure.
2017
- Fabrication, Modeling, and Evaluation of a Digital Output Tilt Sensor With Conductive Microspheres
[Articolo su rivista]
Büthe, L; Vogt, C; Petti, L; Cantarella, G; Münzenrieder, N; Tröster, G
abstract
Recent advances in wearable computing ask for bendable and conformable electronic circuits and sensors, allowing an easy integration into everyday life objects. Here, we present a novel flexible tilt sensor on plastic using conductive microspheres as gravity sensitive pendulum. The sensor provides a digital output of the measurement signal without the need for any additional electronics (e.g., amplifiers) close to the sensing structure. The sensor is fabricated on a free-standing polyimide foil with SU-8 photoresist defining the cavity for the pendulum. The pendulum consists of freely movable conductive microspheres which, depending on the sense of gravity, connect different electric contacts patterned on the polyimide foil. We develop a model of the sensor and identify the amount of microspheres as one of the key parameters in the sensor design, which influences the performance of the sensor. The presented tilt sensor with eight contacts achieves an angular resolution of 22.5° with a hysteresis of 10° and less at a tilt of the sensor plane of 50°. Analysis of the microsphere movements reveals a response time of the sensor at ∼50 ms.
2017
- Ferroelectric-Like Charge Trapping Thin-Film Transistors and Their Evaluation as Memories and Synaptic Devices
[Articolo su rivista]
Daus, A; Lenarczyk, P; Petti, L; Münzenrieder, N; Knobelspies, S; Cantarella, G; Vogt, C; Salvatore, Ga; Luisier, M; Troster, G
abstract
2017
- Gain-Tunable Complementary Common-Source Amplifier Based on a Flexible Hybrid Thin-Film Transistor Technology
[Articolo su rivista]
Petti, L; Loghin, F; Cantarella, G; Vogt, C; Münzenrieder, N; Abdellah, A; Becherer, M; Haeberle, T; Daus, A; Salvatore, G; Troster, G; Lugli, P
abstract
In this letter, we report a flexible complementary common-source (CS) amplifier comprising one p-type spray-coated singlewalled carbon nanotube and one n-type sputtered InGaZnO4 thin-film transistor (TFT). Bottom-gate TFTs were realized on a free-standing flexible polyimide foil using amaximumprocess temperature of 150 degrees C. The resulting CS amplifier operates at 10 V supply voltage and exhibits a gain bandwidth product of 60 kHz. Thanks to the use of a p-type TFT acting as a tunable current source load, the amplifier gain can be programmed from3.5 up to 27.2V/V (28.7 dB). To the best of our knowledge, this is the highest gain ever obtained for a flexible single-stage CS amplifier.
2017
- Oxide Thin-Film Electronics on Carbon Fiber Reinforced Polymer Composite
[Articolo su rivista]
Münzenrieder, N; Costa, J; Cantarella, G; Vogt, C; Petti, L; Daus, A; Knobelspies, S; Tröster, G
abstract
In this letter, the direct fabrication of amorphous indium-gallium-zinc-oxide thin-film transistors (TFTs) and circuits on a commercial carbon fiber reinforced polymer (CFRP) substrate is demonstrated. The CFRP is encapsulated with a ∼ 10.6-μm-thick resin layer, although the surface roughness and temperature sensitivity of the substrate are not ideal for the fabrication of electronic devices, we present depletion mode TFTs exhibiting a field effect mobility of 18.3 cm2V-1-1, and a common source amplifier, providing a voltage gain of 8 dB and a -3 dB cutoff frequency of 11.5 kHz. The amplifier does not require any input bias voltage and can, hence, be directly used to condition signals originating from various transducers, e.g., piezoelectric strain sensors used to monitor the structural integrity of CFRP elements. This opens the way to the fabrication of smart mechanical CFRP parts with integrated structural integrity monitoring systems.
2017
- Solution-processed p-type copper(I) thiocyanate (CuSCN) for low-voltage flexible thin-film transistors and integrated inverter circuits
[Articolo su rivista]
Petti, L; Pattanasattayavong, P; Lin, Yh; Münzenrieder, N; Cantarella, G; Yaacobi-Gross, N; Yan, F; Troster, G; Anthopoulos, Td
abstract
2017
- 3-5 V, 3-3.8 MHz OOK modulator with a-IGZO TFTs for flexible wireless transmitter
[Relazione in Atti di Convegno]
Ishida, K; Meister, T; Knobelspies, S; Münzenrieder, N; Cantarella, G; Salvatore, Ga; Troster, G; Carta, C; Ellinger, ; F,
abstract
2016
- Entirely Flexible On-Site Conditioned Magnetic Sensorics
[Articolo su rivista]
Münzenrieder, N; Karnaushenko, D; Petti, L; Cantarella, G; Vogt, C; Büthe, L; Karnaushenko, Dd; Schmidt, O; Makarov, D; Tröster, G
abstract
2016
- Flexible a-IGZO Phototransistor for Instantaneous and Cumulative UV-Exposure Monitoring for Skin Health
[Articolo su rivista]
Knobelspies, S; Daus, A; Cantarella, G; Petti, L; Münzenrieder, N; Tröster, G; Salvatore, G
abstract
2016
- Flexible In-Ga-Zn-O based circuits with two and three metal layers: Simulation and Fabrication study
[Articolo su rivista]
Cantarella, G; Ishida, K; Petti, L; Münzenrieder, N; Meister, T; Shabanpour, R; Carta, C; Ellinger, F; Troster, G; Salvatore, Ga
abstract
2016
- Metal oxide semiconductor thin-film transistors for flexible electronics
[Articolo su rivista]
Petti, L; Münzenrieder, N; Vogt, C; Faber, H; Büthe, L; Cantarella, G; Bottacchi, F; Anthopoulos, T; Tröster, G
abstract
2016
- Positive charge trapping phenomenon in n-channel thin-film transistors with amorphous alumina gate insulators
[Articolo su rivista]
Daus, A; Vogt, C; Münzenrieder, N; Petti, L; Knobelspies, S; Cantarella, G; Luisier, M; Salvatore, G; Tröster, G
abstract
In this work, we investigate the charge trapping behavior in InGaZnO4 (IGZO) thin-film transistors with amorphous Al2O3 (alumina) gate insulators. For thicknesses ≤10 nm, we observe a positive charge generation at intrinsic defects inside the Al2O3, which is initiated by quantum-mechanical tunneling of electrons from the semiconductor through the Al2O3 layer. Consequently, the drain current shows a counter-clockwise hysteresis. Furthermore, the de-trapping through resonant tunneling causes a drastic subthreshold swing reduction. We report a minimum value of 19 mV/dec at room temperature, which is far below the fundamental limit of standard field-effect transistors. Additionally, we study the thickness dependence for Al2O3 layers with thicknesses of 5, 10, and 20 nm. The comparison of two different gate metals shows an enhanced tunneling current and an enhanced positive charge generation for Cu compared to Cr.
2016
- Radio Frequency Electronics in a-IGZO TFT Technology (Invited)
[Relazione in Atti di Convegno]
Ishida, K; Meister, T; Shabanpour, R; Boroujeni, Bk; Carta, C; Cantarella, G; Petti, L; Münzenrieder, N; Salvatore, Ga; Troster, G; Ellinger, F
abstract
This paper reviews the recent progress of active high-frequency electronics on plastic, and gives an outlook towards future advances of radio-frequency electronics in the amorphous Indium Gallium Zinc Oxide (a-IGZO) thin-film transistor (TFT) technology. Our a-IGZO technology is mechanically flexible, bendable and stretchable. A 0.5 mu m TFT achieved a measured transit frequency of 138 MHz. We have presented several high-frequency circuits integrated in this a-IGZO technology, including several RF amplifiers and a fully-integrated AM receiver. The receiver consists of a four-stage cascode amplifier, an amplitude detector, a baseband amplifier, and a filter. At a DC current of 7.2 mA and a supply of 5 V, a conversion gain above 15dB was measured from 2 to 20MHz. Based on these works, we are investigating a wireless transmitter to be fully integrated on a plastic film. Some simulation results of a ring-oscillator based on-off-keying modulator and an LC voltage controlled oschillator under investigation are presented.
2016
- Sensors: Entirely Flexible On-Site Conditioned Magnetic Sensorics (Adv. Electron. Mater. 8/2016)
[Working paper]
Münzenrieder, N; Karnaushenko, D; Petti, L; Cantarella, G; Vogt, C; Büthe, L; Karnaushenko, D D; Schmidt, O; Makarov, D; Tröster, G
abstract
2016
- 20.3dB 0.39mW AM Detector with Single-Transistor Active Inductor in Bendable a-IGZO TFT
[Relazione in Atti di Convegno]
Meister, T; Ishida, K; Shabanpour, R; K-Boroujeni, B; Carta, C; Münzenrieder, N; Petti, L; Cantarella, G; Salvatore, Ga; Troster, G; Ellinger, F
abstract
This paper presents an AM detector circuit in a bendable a-IGZO TFT technology. The circuit is based on a common-source stage loaded with a single-ended active inductor, which uses only one active transistor. This active inductor is the key element for the achieved circuit performance. The detector circuit consumes only 0.39 mW, which is almost a tenfold improvement over previous works in the same technology and crucial for mobile and wearable applications. At the same time it has the smallest chip area. The detector provides a conversion gain of 20.3 dB and an RF -3dB-bandwidth of around 7.5 MHz. At fc=13.56 MHz it has 11.6 dB gain, which also allows its use in this unlicensed ISM radio band for RFID and smart label applications.
2015
- Design and simulation of a 800 Mbit/s data link for magnetic resonance imaging wearables
[Relazione in Atti di Convegno]
Vogt, C; Buthe, L; Petti, L; Cantarella, G; Munzenrieder, N; Daus, A; Troster, G
abstract
This paper presents the optimization of electronic circuitry for operation in the harsh electro magnetic (EM) environment during a magnetic resonance imaging (MRI) scan. As demonstrator, a device small enough to be worn during the scan is optimized. Based on finite element method (FEM) simulations, the induced current densities due to magnetic field changes of 200 T s(-1) were reduced from 1 x 10(10) A m(-2) by one order of magnitude, predicting error-free operation of the 1.8 V logic employed. The simulations were validated using a bit error rate test, which showed no bit errors during a MRI scan sequence. Therefore, neither the logic, nor the utilized 800 Mbit s(-1) low voltage differential swing (LVDS) data link of the optimized wearable device were significantly influenced by the EM interference. Next, the influence of ferro-magnetic components on the static magnetic field and consequently the image quality was simulated showing a MRI image loss with approximately 2 cm radius around a commercial integrated circuit of 1 x 1 cm(2). This was successively validated by a conventional MRI scan.
2015
- Digital output flexible tilt sensor with conductive microspheres
[Relazione in Atti di Convegno]
Büthe, L; Vogt, C; Petti, L; Cantarella, G; Tröster, G; Münzenrieder, N
abstract
2015
- Flexible In-Ga-Zn-O Thin-Film Transistors on Elastomeric Substrate Bent to 2.3% Strain
[Articolo su rivista]
Cantarella, G; Münzenrieder, N; Petti, L; Vogt, C; Buthe, L; Salvatore, G; Daus, A; Troster, G
abstract
In this letter, a photolithographic fabrication process is used to manufacture indium-gallium-zinc-oxide thin-film transistors (TFTs) with mobilities > 10 cm ^{2}/Vs directly on a 80 μ m thick polydimethylsiloxane (PDMS) substrate. Once the fabrication is completed, the PDMS is detached from a silicon wafer used as carrier substrate. Due to the thermal mismatch between silicon and PDMS, the release results in a reduction of the PDMS area by 7.2%, which leads to the formation of out-of-plane wrinkles on the TFT surface. The reflattening of the wrinkles under tensile strain enables device functionality, while the TFTs are bent up to 2.3% strain. Mechanical stability of the TFTs with our wrinkled approach is shown by electrically characterizing them at bending radii down to 6 mm.
2015
- Flexible Quasi-Vertical In-Ga-Zn-O Thin-Film Transistor With 300-nm Channel Length
[Articolo su rivista]
Petti, L; Frutiger, A; Munzenrieder, N; Salvatore, Ga; Buthe, L; Vogt, C; Cantarella, G; Troster, G
abstract
In this letter, we report a flexible Indium-Gallium-Zinc-Oxide quasi-vertical thin-film transistor (QVTFT) with 300-nm channel length, fabricated on a free-standing polyimide foil, using a low-temperature process <150 degrees C. A bilayer lift-off process is used to structure a spacing layer with a tilted sidewall and the drain contact on top of the source electrode. The resulting quasi-vertical profile ensures a good coverage of the successive device layers. The fabricated flexible QVTFT exhibits an ON/OFF current ratio of 10(4), a threshold voltage of 1.5 V, a maximum transconductance of 0.73 mu S mu m(-1), and a total gate capacitance of 76 nF mu m(-1). From S-parameter measurements, we extracted a transit frequency of 1.5 MHz. Furthermore, the flexible QVTFT is fully operational when bent to a tensile radius of 5 mm.
2015
- Integration of solution-processed (7,5) SWCNTs with sputtered and spray-coated metal oxides for flexible complementary inverters
[Relazione in Atti di Convegno]
Petti, L; Bottacchi, F; Münzenrieder, N; Faber, H; Cantarella, G; Vogt, C; Büthe, L; Namal, I; Späth, F; Hertel, T; Anthopoulos, T; Tröster, G
abstract
2015
- Low-temperature spray-deposited indium oxide for flexible thin-film transistors and integrated circuits
[Articolo su rivista]
Petti, L; Faber, H; Münzenrieder, N; Cantarella, G; Patsalas, P; Tröster, G; Anthopoulos, T
abstract
Indium oxide (In2O3) films were deposited by ultrasonic spray pyrolysis in ambient air and incorporated into bottom-gate coplanar and staggered thin-film transistors. As-fabricated devices exhibited electron-transporting characteristics with mobility values of 1 cm2V-1s-1 and 16 cm2V-1s-1 for coplanar and staggered architectures, respectively. Integration of In2O3 transistors enabled realization of unipolar inverters with high gain (5.3 V/V) and low-voltage operation. The low temperature deposition (≤250 °C) of In2O3 also allowed transistor fabrication on free-standing 50 μm-thick polyimide foils. The resulting flexible In2O3 transistors exhibit good characteristics and remain fully functional even when bent to tensile radii of 4 mm.
2015
- Morphological changes in rivers of South Tyrol (Italian Alps) attributable to climate variations since the Little Ice Age
[Poster]
Marchese, E; Scorpio, V; Comiti, F
abstract
2015
- Stretchable and Conformable Oxide Thin-Film Electronics
[Articolo su rivista]
Münzenrieder, N; Cantarella, G; Vogt, C; Petti, L; Buthe, L; Salvatore, Ga; Fang, Y; Andri, R; Lam, Y; Libanori, R; Widner, D; Studart, Ar; Troster, G
abstract
Stretchable large-area high-performance amorphous oxide thin-film electronics fabricated using locally reinforced composite elastomers or wavy structures are functional while elongated by >200% and after 4000 stretching and relaxation cycles. 2D stretchable sensors, amplifiers, and circuits for wireless power transmission are conformably wrapped around arbitrary 3D structures and enable sensor systems for electronic implants and skins.
2015
- Stretchable Electronics: Stretchable and Conformable Oxide Thin-Film Electronics (Adv. Electron. Mater. 3/2015)
[Working paper]
Münzenrieder, N; Cantarella, G; Vogt, C; Petti, L; Büthe, L; Salvatore, G; Fang, Y; Andri, R; Lam, Y; Libanori, R; Studart, A; Widner, D; Tröster, G
abstract
2014
- Contact resistance and overlapping capacitance in flexible sub-micron long oxide thin-film transistors for above 100 MHz operation
[Articolo su rivista]
Münzenrieder, N; Salvatore, G; Petti, L; Zysset, C; Büthe, L; Vogt, C; Cantarella, G; Tröster, G
abstract
In recent years new forms of electronic devices such as electronic papers, flexible displays, epidermal sensors, and smart textiles have become reality. Thin-film transistors (TFTs) are the basic blocks of the circuits used in such devices and need to operate above 100 MHz to efficiently treat signals in RF systems and address pixels in high resolution displays. Beyond the choice of the semiconductor, i.e., silicon, graphene, organics, or amorphous oxides, the junctionless nature of TFTs and its geometry imply some limitations which become evident and important in devices with scaled channel length. Furthermore, the mechanical instability of flexible substrates limits the feature size of flexible TFTs. Contact resistance and overlapping capacitance are two parasitic effects which limit the transit frequency of transistors. They are often considered independent, while a deeper analysis of TFTs geometry imposes to handle them together; in fact, they both depend on the overlapping length (LOV) between source/drain and the gate contacts. Here, we conduct a quantitative analysis based on a large number of flexible ultra-scaled IGZO TFTs. Devices with three different values of overlap length and channel length down to 0.5 μm are fabricated to experimentally investigate the scaling behavior of the transit frequency. Contact resistance and overlapping capacitance depend in opposite ways on LOV. These findings establish routes for the optimization of the dimension of source/drain contact pads and suggest design guidelines to achieve megahertz operation in flexible IGZO TFTs and circuits.
2014
- Coupling model for an extended-range plasmonic optical transformer scanning probe
[Articolo su rivista]
Polyakov, A.; Melli, M.; Cantarella, G.; Weber-Bargioni, A.; Schuck, P.; Cabrini, S.
abstract
The expansion of nanoscale optics has generated a variety of scanning probe geometries that yield spatial resolution below 10 nm. In this work, we present a physical model for coupling far-field radiation to plasmonic modes on the surface of a scanning probe, and propose a scheme for extending the working distance of such a probe. In a subsurface application, an optical transformer at the tip of a probe can be coupled to a remote near-field antenna placed inside the sample at a distance away from the surface, expanding the effective working distance up to 100 nm. © 2014 CIOMP. All rights reserved 2047-7538/14.
2014
- Erratum: Coupling model for an extended-range plasmonic optical transformer scanning probe (Light: Science & Applications (2014) 3, (e195) DOI: 10.1038/lsa.2014.76)
[Articolo su rivista]
Polyakov, A.; Melli, M.; Cantarella, G.; Schwartzberg, A.; Weber-Bargioni, A.; Schuck, P.; Cabrini, S.
abstract