Yu Di, Zheng Zhipeng, Liu Jiadong, Xiao Hongyuan, Huangfu Geng, Guo Yiping
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.
Nanomicro Lett. 2021 Apr 30;13(1):117. doi: 10.1007/s40820-021-00649-9.
For traditional piezoelectric sensors based on poled ceramics, a low curie temperature (T) is a fatal flaw due to the depolarization phenomenon. However, in this study, we find the low T would be a benefit for flexible piezoelectric sensors because small alterations of force trigger large changes in polarization. BaTiSnO (BTS) with high piezoelectric coefficient and low T close to human body temperature is taken as an example for materials of this kind. Continuous piezoelectric BTS films were deposited on the flexible glass fiber fabrics (GFF), self-powered sensors based on the ultra-thin, superflexible, and polarization-free BTS-GFF/PVDF composite piezoelectric films are used for human motion sensing. In the low force region (1-9 N), the sensors have the outstanding performance with voltage sensitivity of 1.23 V N and current sensitivity of 41.0 nA N. The BTS-GFF/PVDF sensors can be used to detect the tiny forces of falling water drops, finger joint motion, tiny surface deformation, and fatigue driving with high sensitivity. This work provides a new paradigm for the preparation of superflexible, highly sensitive and wearable self-powered piezoelectric sensors, and this kind of sensors will have a broad application prospect in the fields of medical rehabilitation, human motion monitoring, and intelligent robot.
对于基于极化陶瓷的传统压电传感器而言，居里温度（T）较低是一个致命缺陷，因为存在去极化现象。然而，在本研究中，我们发现低居里温度对柔性压电传感器有益，因为力的微小变化会引发极化的大幅改变。以具有高压电系数且居里温度接近人体体温的钛锡酸钡（BTS）为例来说明这类材料。连续的压电BTS薄膜沉积在柔性玻璃纤维织物（GFF）上，基于超薄、超柔性且无极化的BTS-GFF/PVDF复合压电薄膜的自供电传感器用于人体运动传感。在低力区域（1 - 9 N），传感器具有出色的性能，电压灵敏度为1.23 V/N，电流灵敏度为41.0 nA/N。BTS-GFF/PVDF传感器可用于高灵敏度地检测落水的微小力、手指关节运动、微小表面变形以及疲劳驾驶。这项工作为制备超柔性、高灵敏度和可穿戴自供电压电传感器提供了一种新范式，并且这类传感器在医疗康复、人体运动监测和智能机器人领域将具有广阔的应用前景。
