High-Density Flexible Piezoelectric Sensor Array With Double Working Modes

Flexible and self-powered sensing device has aroused considerable interest in the field of the Internet of Things (IoT) and artificial intelligence (AI) in recent years. For more detailed and sensitive perception of the surroundings and external stimuli, sensors with high density and sensitivity are highly desirable. Here, this article reported a simple and low-cost strategy to realize a high-performance flexible piezoelectric sensor array composed of 30 sensing points with a high density of 11.11 cm $^{-{2}}$ . The piezoelectric sensor array was analyzed by a finite-element model and characterized through sound pressure measurement and wrist bending for motion monitoring under ${d}_{{33}}$ and ${d}_{{31}}$ modes, respectively. The flexible sensor array with the total thickness of 125 $\mu \text{m}$ exhibits a high sensitivity of 447.82 mV $\cdot $ kPa $^{-{1}}$ with an ultralow detection limit of $\sim 3.60$ Pa. Our work provides a simple strategy for the application potential in smart wearable electronics and human–machine interaction (HMI) areas.