文献类型：期刊文献

英文题名：Air-cavity-free multiphase composite piezoelectrets with high piezoelectric sensitivity for self-powered flexible sensors and energy harvesters

作者：Liu, Yuji[1];Wu, Chengyuan[1];Qiu, Xunlin[1];Xu, Peng[1];Xiang, Yanxun[1];Xuan, Fu-Zhen[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai Key Lab Intelligent Sensing & Detect Tech, Shanghai 200237, Peoples R China

年份：2024

卷号：37

外文期刊名：APPLIED MATERIALS TODAY

收录：;EI(收录号：20240715553706);WOS:【SCI-EXPANDED(收录号:WOS:001180644300001)】；

基金：Financial support from the National Natural Science Foundation of China (Nos. 12174102 and 12025403) and the National Key Research and Development Program of China (No. 2021YFC3001802) is gratefully acknowledged.

语种：英文

外文关键词：Multiphase composite; Piezoelectret; Self -powered sensor; Electronic device; Energy harvester

摘要：Piezoelectrets (also called ferroelectrets) combine large piezoelectricity with mechanical flexibility and elastic compliance, and therefore attract much attention from academia and industry. Piezoelectrets studied so far are mostly polymer foams or polymer-film systems with air-filled cavities as the soft phase. Herein, we propose multiphase composites as air-cavity-free piezoelectrets with high piezoelectric sensitivity. As compared with conventional piezoelectrets, soft polydimethylsiloxane (PDMS) elastomer, rather than air, acts as the soft phase of the multiphase composite piezoelectrets (MPCPs). Space-charge electret fluoroethylenepropylene is used for the hard phase. PDMS has breakdown strength and relative permittivity higher than those of air, which is beneficial for improving the piezoelectric sensitivity of the MPCPs. Both layer-structured and PMDS-filled tubular-channel MPCPs show prominent piezoelectricity. Particularly, the piezoelectric d33 coefficient of the MPCPs with patterned structure reaches about 886 pC/N at a surface potential of -2962 V, while the d33 of its airfilled counterpart saturates at about 294 pC/N for surface potentials above -1000 V. By inserting a polypropylene (PP) insulating layer between the FEP/PDMS composites and their top electrode, the MPCPs exhibit large piezoelectric sensitivity with good long-term stability. Self-powered sensors and energy harvesters are fabricated to demonstrate great application potential of MPCPs. Using the MPCP sensors, body motion and vital physiological signals such as radial artery pulse and respiration are effectively monitored. Meanwhile, the MPCP harvester can simultaneously light up 32 commercial LED lights by pressing with a human finger. Our study paves the way for preparation of air-cavity-free MPCPs with high piezoelectric sensitivity for different sensing and energy harvesting applications.