Superflexible and Lead-Free Piezoelectric Nanogenerator as a Highly Sensitive Self-Powered Sensor for Human Motion Monitoring

• Published in: Nano-micro letters Vol. 13; no. 1; pp. 117 - 12
• Main Authors: Yu, Di, Zheng, Zhipeng, Liu, Jiadong, Xiao, Hongyuan, Huangfu, Geng, Guo, Yiping
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.12.2021; Springer Nature B.V; SpringerOpen
• Subjects: Body temperature; Curie temperature; Depolarization; Driver fatigue; Engineering; Fabrics; Finger jointing; Glass fibers; Human motion; Human motion sensing; Lead free; Monitoring; Nanogenerator; Nanogenerators; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; Piezoelectric films; Piezoelectric sensors; Polarization; Rehabilitation; Robot dynamics; Sensitivity; Sensors; Superflexible; Water drops; Wearable technology; Superflexible; Human motion sensing; Piezoelectric sensors; Curie temperature
• ISSN: 2311-6706; 2150-5551; 2150-5551
• DOI: 10.1007/s40820-021-00649-9

Highlights Continuous piezoelectric BaTi 0.88 Sn 0.12 O 3 (BTS) films were deposited on glass fiber fabrics successfully. Superflexible, highly sensitive self-powered piezoelectric sensors were fabricated based on polarization-free BTS. Low curie temperature would be a benefit for flexible piezoelectric sensors because small alterations of force will trigger large changes in polarization. The superflexible sensors are highly desirable for wearable devices to detect human motion. For traditional piezoelectric sensors based on poled ceramics, a low curie temperature ( T c ) is a fatal flaw due to the depolarization phenomenon. However, in this study, we find the low T c would be a benefit for flexible piezoelectric sensors because small alterations of force trigger large changes in polarization. BaTi 0.88 Sn 0.12 O 3 (BTS) with high piezoelectric coefficient and low T c 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 −1 and current sensitivity of 41.0 nA N −1 . 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.