Robust self-gated-carriers enabling highly sensitive wearable temperature sensors

Abstract

Wearable temperature sensors can obtain and convey accurate temperature information on the human body and objects. However, most reported wearable temperature sensors suffer from limitations, such as high fabrication cost and low working efficiency, sensing performance, and scalability, which impede their broad application in wearable fields. In this work, a new type of metal–semiconductor–metal (MSM) self-gated device based on NiO/Ni heterostructure frameworks is fabricated and employed in wearable high-performance temperature sensors. The MSM self-gated device is prepared via a facile and controllable in situ oxidation method and demonstrates efficient charge transportation, excellent thermal conductivity [3.74 W (m K−1)], and high thermal diffusivity (9.39 mm2 s−1). The obtained temperature sensors exhibit high sensitivity (−5.04% °C−1), wide working range (−15 to 80 °C), and excellent stability (more than three months) and have been applied to monitor the temperature of objects and the human body. In particular, a flexible temperature sensor array is fabricated to measure the spatially resolved temperature distribution. The array demonstrates the bright application prospects of the sensors in the fields of human–machine interfaces and intelligent medical systems.