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

Abstract

For traditional piezoelectric sensors based on poled ceramics, a low curie temperature (Tc) is a fatal flaw due to the depolarization phenomenon. However, in this study, we find the low Tc would be a benefit for flexible piezoelectric sensors because small alterations of force trigger large changes in polarization. BaTi0.88Sn0.12O3 (BTS) with high piezoelectric coefficient and low Tc 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.

Engineering the Defects and Microstructures in Ferroelectrics for Enhanced/Novel Properties: An Emerging Way to Cope with Energy Crisis and Environmental Pollution

“…[ 172 ] By using Sr doped BaTiO 3 thin films deposited on glass fiber fabrics, we reported a superflexible PENG based self‐powered sensor that is highly sensitive to human motion monitoring. [ 173 ] Bai et al [ 91 , 93 ] have reported that the photoferroelectrics can also be used for multisource energy harvesting‐sensing.…”

The Progress of Research into Flexible Sensors in the Field of Smart Wearables

“…Feng et al [ 184 ] developed a motion monitoring technique for flexible integrated sensor systems that is able to independently measure bending strain and pressure coupled with a low-cost and simple manufacturing process. Yu et al [ 185 ] prepared ultra-flexible and lead-free piezoelectric nanogenerators as highly sensitive self-powered sensors for monitoring human motion, which displayed promise for applications in smart healthcare.…”

Self-Healing, Self-Adhesive and Stable Organohydrogel-Based Stretchable Oxygen Sensor with High Performance at Room Temperature

“…In recent years, with the rapid development of the Internet of Things (IoT) and the growing requirements of people’s life quality, various sensors used for monitoring health and environmental quality have gradually entered people’s daily lives to enhance people’s living standards [ 1 – 5 ]. For instance, gas sensors can be exploited to monitor the content of various gases in the environment [ 6 – 9 ].…”