Integrating In‐Plane Thermoelectricity and Out‐Plane Piezoresistivity for Fully Decoupled Temperature‐Pressure Sensing

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2024-03, Vol.20 (12), p.e2307800-n/a
• Main Authors: Wang, Jincheng, Chen, Rui, Ji, Dongsheng, Xu, Wenjun, Zhang, Wenzhuo, Zhang, Chen, Zhou, Wei, Luo, Tao
• Format: Article
• Language: English
• Subjects: Algorithms; Artificial intelligence; Biomedical materials; Contact pressure; Crosstalk; Decoupling; Error analysis; flexible bimodal sensors; Flexible components; Orthogonality; Piezoresistivity; pressure sensing; Sensor arrays; Sensors; temperature sensing; Thermoelectricity
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202307800

A flexible sensor that simultaneously senses temperature and pressure is crucial in various fields, such as human‐machine interaction, artificial intelligence, and biomedical applications. Previous research has mainly focused on single‐function flexible sensors for e‐skins or smart devices, and integrated bimodal sensing of temperature and pressure without complex crosstalk decoupling algorithms remains challenging. In this work, a flexible bimodal sensor is proposed that utilizes spatial orthogonality between in‐plane thermoelectricity and out‐plane piezoresistivity, which enables fully decoupled temperature‐pressure sensing. The proposed bimodal sensor exhibits a high sensitivity of 281.46 µV K−1 for temperature sensing and 2.181 kPa−1 for pressure sensing. In the bimodal sensing mode, the sensor exhibits negligible mutual interference, providing a measurement error of ± 7% and ± 8% for temperature and pressure, respectively, within a 120 kPa pressure range and a 40 K temperature variation. Additionally, simultaneous spatial mapping of temperature and pressure with a bimodal sensor array enables contact shape identification with enhanced accuracy beyond the limit imposed by the number of sensing units. The proposed integrated bimodal sensing strategy does not require complex crosstalk decoupling algorithms, which represents a significant advancement in flexible sensors for applications that necessitate simultaneous sensing of temperature and pressure. The demand for simultaneous temperature and pressure sensing with minimal interference is on the rise, particularly in the fields of robotics and wearable devices. A flexible bimodal sensor, which integrates in‐plane thermoelectricity and out‐plane piezoresistivity, is developed to fulfill this need. This sensor exhibits negligible mutual interference, marking a significant advancement in flexible sensor technology.