E-textile technology review - from materials to application

Wearable devices are ideal for personalized electronic applications in several domains such as healthcare, entertainment, sports and military. Although wearable technology is a growing market, current wearable devices are predominantly battery powered accessory devices, whose form factors also preclude them from utilizing the large area of the human body for spatiotemporal sensing or energy harvesting from body movements. E-textiles provide an opportunity to expand on current wearables to enable such applications via the larger surface area offered by garments, but consumer devices have been few and far between because of the inherent challenges in replicating traditional manufacturing technologies (that have enabled these wearable accessories) on textiles. Also, the powering of e-textile devices with battery energy like in wearable accessories, has proven incompatible with textile requirements for flexibility and washing. Although current e-textile research has shown advances in materials, new processing techniques, and one-off e-textile prototype devices, the pathway to industry scale commercialization is still uncertain. This paper reports the progress on the current technologies enabling the fabrication of e-textile devices and their power supplies including textile-based energy harvesters, energy storage mechanisms, and wireless power transfer solutions. It identifies factors that limit the adoption of current reported fabrication processes and devices in the industry for mass-market commercialization

Additively manufactured BaTiO

From PubMed via Jisc Publications RouterHistory: received 2021-04-02, revised 2021-05-09, accepted 2021-05-14Publication status: ppublishPiezoelectric ceramics, such as BaTiO , have gained considerable attention in bone tissue engineering applications thanks to their biocompatibility, ability to sustain a charged surface as well as improve bone cells' adhesion and proliferation. However, the poor processability and brittleness of these materials hinder the fabrication of three-dimensional scaffolds for load bearing tissue engineering applications. For the first time, this study focused on the fabrication and characterisation of BaTiO composite scaffolds by using a multi-material 3D printing technology. Polycaprolactone (PCL) was selected and used as dispersion phase for its low melting point, easy processability and wide adoption in bone tissue engineering. The proposed single-step extrusion-based strategy enabled a faster and solvent-free process, where raw materials in powder forms were mechanically mixed and subsequently fed into the 3D printing system for further processing. PCL, PCL/hydroxyapatite and PCL/BaTiO composite scaffolds were successfully produced with high level of consistency and an inner architecture made of seamlessly integrated layers. The inclusion of BaTiO ceramic particles (10% wt.) significantly improved the mechanical performance of the scaffolds (54 ± 0.5 MPa) compared to PCL/hydroxyapatite scaffolds (40.4 ± 0.1 MPa); moreover, the presence of BaTiO increased the dielectric permittivity over the entire frequency spectrum and tested temperatures. Human osteoblasts Saos-2 were seeded on scaffolds and cellular adhesion, proliferation, differentiation and deposition of bone-like extracellular matrix were evaluated. All tested scaffolds (PCL, PCL/hydroxyapatite and PCL/BaTiO ) supported cell growth and viability, preserving the characteristic cellular osteoblastic phenotype morphology, with PCL/BaTiO composite scaffolds exhibiting higher mineralisation (ALP activity) and deposited bone-like extracellular matrix (osteocalcin and collagen I). The single-step multi-material additive manufacturing technology used for the fabrication of electroactive PCL/BaTiO composite scaffolds holds great promise for sustainability (reduced material waste and manufacturing costs) and it importantly suggests PCL/BaTiO scaffolds as promising candidates for load bearing bone tissue engineering applications to solve unmet clinical needs. [Abstract copyright: Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.

Piezoelectric catalysis for efficient reduction of CO₂ using lead-free ferroelectric particulates

The increase in global energy demand, together with a rise in carbon dioxide (CO2) levels have encouraged research into the reduction of CO2 into useful chemicals and fuels. In this paper, we demonstrate the piezo-catalytic reduction of CO2 using lead-free lithium-doped potassium sodium niobate (KNN) ferroelectric ceramic particulates. The application of acoustic waves generated by ultrasound to a suspension of the ceramics particles creates pressure waves result in a large change in the spontaneous polarisation of the KNN particles via the piezoelectric effect, which in turn creates surfaces charges for CO2 reduction. The effect of CO2 gas concentration, the presence of dissolved species, and catalyst loading on piezo-catalytic performance are explored. By optimization of the piezo-catalytic effect, a promising piezo-catalytic CO2 reduction rate of 438 μmol g−1 h−1 is achieved, which is much larger than the those obtained from pyro-catalytic effects. This efficient and polarisation tuneable piezo-catalytic route has potential to promote the development of CO2 reduction via the utilisation of vibrational energy for environmental benefit.</p