Ultrathin and Flexible Thermal Perception Sensor for Matter and Pressure Detection

Abstract

In this article, an ultrathin and flexible thermal perception (FTP) sensor with a fingerprint-like sensing structure is proposed. The developed FTP sensor features a sandwich structure formed by biocompatible polyimide (PI), gold thermistors, and Parylene C layers with a total thickness of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8~\mu \text{m}$ </tex-math></inline-formula> . Meanwhile, multisensory functions including temperature and pressure sensing, as well as matter recognition are realized. Specifically, the FTP sensor shows an ultrafast response time of less than 0.12 s and 52 ms for matter and temperature detection, respectively, while various matters information such as PI, rubber, and steel, can be easily distinguished. Besides, the ultrathin design allows the sensor to gain signal stability of less than 0.3% even at a curvature up to 0.25 mm−1. Furthermore, the FTP sensor achieved a sensitivity of 812 mV/kPa for pressure sensing after being partially covered with a thermal conductive powder-doped silicone film. In short, the demonstrated functionality of this ultrathin FTP sensor combined with its simple fabrication holds the prospect of further advancing and deploying this device as a promising sensory system for mimicking human interaction.