Ultra-sensitive, stretchable, and bidirectional wearable strain sensor for human motion detection

Abstract

Flexible strain sensors are widely used in electronic skin, medical diagnosis, and human movement and health detection. It is urgent to prepare portable high-performance flexible sensors with excellent sensitivity, ultra-low detection limit, broad detection range and simple structure. In this work, the MXene/SnS₂/SA sensitive material was sprayed on a PDMS substrate and encapsulated on the top layer by PDMS. A bidirectional sandwich structured sensor with good stretchability (up to 70% strain), adjustable linear sensing range (0–60% strain), ultra-high sensitivity (a giant gauge factor as high as 7178), excellent repeatability and stability (>600 cycles), and quick response was successfully fabricated. The sensor also demonstrates a large pressure sensing range (0–350 kPa), high sensitivity (0.97 kPa⁻¹), and fast response/recovery time (300 ms/200 ms). The sensor has superior application potential in detecting subtle health signals and large-scale motion signals. The device has a strong structure, excellent performance and stable detection output, and is expected to find application in wearable electronic devices.