Università degli studi di Modena e Reggio Emilia

Graded lattice scaffolds based on rhombic dodecahedral (RD) elementary unit cell geometry were manufactured in 316L stainless steel (SS) by laser powder bed fusion (LPBF). Two different strategies based on varying strut thickness layer-by-layer in the building direction were adopted to obtain the graded scaffolds: a) decreasing strut size from core to edge to produce the dense-in (DI) structure and b) increasing strut size in the same direction to produce the dense-out (DO) structure. Both graded structures (DI and DO) were constructed with specular symmetry with respect to the central horizontal axis. Structural, mechanical, and biological characterizations were carried out to evaluate feasibility of designing appropriate biomechanical performances of graded scaffolds in the perspective of bone tissue regeneration. Results showed that mechanical behavior is governed by graded geometry, while printing parameters influence structural properties of the material such as density, textures, and crystallographic phases. The predominant failure mechanism in graded structures initiates in correspondence of thinner struts, due to high stress concentrations on strut junctions. Biological tests evidenced better proliferation of cells in the DO graded scaffold, which in turn exhibits mechanical properties close to cortical bone. The combined control of grading strategy, printing parameters and elementary unit cell geometry can enable implementing scaffolds with improved biomechanical performances for bone tissue regeneration.

The development of “intelligent” floors is a growing interest, but often the ensuing solutions involve high production costs as well as complicated installation and management. Aim of this paper is to propose a novel smart floor that makes use of an energy harvesting system in order to allow people localization and to track their movements in an indoor environment. The contribution starts from reviewing the state of the art of smart floor solutions, which are categorized according to the different applications they are addressed to. The system developed in this research is based on capacitive sensors that are mounted on a polymeric support and embedded between a bulk wooden base and floating parquet flooring. The paper outlines the detailed architecture of the proposed apparatus and reports the results of the preliminary test phase. The proposed solution is part of HDOMO, an Ambient Assisted Living (AAL) project aiming at the development of smart solutions for active aging.