Bionic Microstructure-Inspired Dual-Mode Flexible Sensor with Photothermal Effect for Ultrasensitive Temperature and Strain Monitoring

Abstract

Flexible dual-mode sensors play a pivotal role in information exchange between humans and the environment. However, achieving dual-mode sensing encompassing both flexibility and stretchability, while accurately quantifying stimulus signals such as temperature, remains a significant challenge. This paper presents a novel flexible dual-mode strain/temperature sensor (DMSTS) that utilizes graphite powder (GR)/polyaniline (PANI)/silicone rubber composites, inspired by the bionic microstructure of a centipede's foot. The DMSTS exhibits an exceptional strain detection range (≈177%), and a low limit of detection (0.5% strain). Regarding temperature sensing, the DMSTS demonstrates a positive temperature coefficient effect within the range of 25–90 °C, with an ultrahigh sensitivity of 10.3 within the 75–90 °C range. Leveraging the photothermal characteristics of GR and PANI, the DMSTS holds significant promise for applications in human motion detection, infrared imaging, and photothermal effects. When integrated into an intelligent sensing system, it enables dynamic noncontact temperature measurement, human micro-expression detection, and motion joint monitoring. Additionally, by incorporating a flexible thermochromic film with color-changing ink, the DMSTS transforms temperature detection into a visually intuitive operation. With its versatile dual-mode sensing capabilities, the DMSTS exhibits substantial potential in the fields of wearable electronics and healthcare.