In this context, the City University of Hong Kong research team has developed a flexible, permeable and high-output tertiary piezoelectric ceramic composite fabric based on template-assisted sol-gel method, with unique internal multistage structure that can effectively strengthen mechanical properties.
The piezoelectric composite fabric is composed of PZT ceramic skeleton and P (VDF-TRFe) coating, and copper mesh is attached on both sides as electrodes. Similar to the fabric template used, the submillimeter level multi-strand ceramic fibers that are intertwined constitute the PZT ceramic skeleton, while the micron level PZT fibers that make up the ceramic fiber bundle are secondary structures. The P (VDF-TrFE) film coated with PZT ceramic framework provides better mechanical and piezoelectric properties for the piezoelectric composite fabric. The unique internal multi-stage pore structure also makes the fabric has good air permeability, the air permeability is up to 45.1mm /s.
Compared with the traditional piezoelectric composite, the piezoelectric composite fabric has higher Young's modulus (0.35gpa), fracture strength, elongation, toughness (0.125MJ /m3) and fracture energy in mechanical properties. In terms of piezoelectric properties, the fabric is capable of producing an open-circuit voltage of 128 V, enough to light 75 leds simultaneously.
Air permeability and mechanical properties of piezoelectric ceramic composite fiber
To evaluate the potential applications of the piezoelectric composite fabric in human motion monitoring and energy collection, the researchers used it as an insole for the sole of a shoe to convert the energy generated by human walking into electrical signals. When it was used as a pedometer, 63 steps were recorded successfully within 2min and displayed on the phone screen at the same time. When used as an energy harvesting device, the voltage stored in the capacitor increases to 3.1V during the 36s trample. The energy stored in the capacitor can be further used to power the electronic meter, which can continue to operate for 16s.
Energy harvesting device based on piezoelectric composite fabric
The research of the piezoelectric fabric design multistage structure and manufacture of functional concept to improve the traditional piezoelectric properties of piezoelectric material provides a new train of thought, at the same time, it pay more attention to air permeability, piezoelectric, flexibility and tenacity on balance strategy to further promote the functional materials in wearable devices and the application of the flexible electronics.
source: Shen Dun Sha Xian
https://mp.weixin.qq.com/s?__biz=MzA4MTY5NzMxMw==&mid=2649436746&idx=2&sn=4aaee227f892d5444eecc4dd29ca81d0&chksm=878e9d04b0f9141257eed123fc5877e56f43c5c39057e95cbb02420a67ae89e61187ea6e0740&mpshare=1&scene=1&srcid=08057LlCtw3CCiktUo5QA8hz&sharer_sharetime=1628151838828&sharer_shareid=ff5f2139d31a4580928c819c5eb948df&exportkey=ARGO48GMK1gCr8jEhPTorvM%3D&pass_ticket=%2FDlWc7oOYifDI7WRdzg6tQnqP6Acr0TsNr0RtL%2BR1I97bWUjGRTYTHsk1%2Fr1wNwv&wx_header=0#rd