High-sensitivity self-powered temperature/pressure sensor based on flexible Bi-Te thermoelectric film and porous microconed elastomer

Abstract

• A self-powered Bi-Te and porous microcone-based temperature/pressure sensor is presented. • A flexible TEG could harvest body heat to power pressure sensor and sense temperature. • Bi-Te based TE thin film with heat sink achieves a high-precision temperature sensor. • The porous microconed architectures greatly enhance the sensitivity of pressure sensor. Electronic skins are artificial skin-type multifunctional sensors, which hold great potentials in intelligent robotics, limb prostheses and human health monitoring. However, it is a great challenge to independently and accurately read various physical signals without power supplies. Here, a self-powered flexible temperature-pressure bimodal sensor based on high-performance thermoelectric films and porous microconed conductive elastic materials is presented. Through introducing flexible heat-sink design and harvesting body heat energy, the thin-film thermoelectric device could not only precisely sense temperature signal but also drive the pressure sensor for detecting external tactile stimulus. The integration of Bi-Te based thermoelectric film with high stability in wide temperature range enables the sensor to sense the ambient temperature with high resolution (<0.1 K) as well as excellent sensitivity (3.77 mV K –1 ). Meanwhile, the porous microconed elastomer responds to pressure variation with low-pressure detection (16 Pa) and a high sensitivity of 37 kPa –1 . Furthermore, the bimodal sensor could accurately and simultaneously monitor human wrist pulse and body temperature in real time, which demonstrates promising applications in self-powered electronic skins for human health monitoring systems.