Multilayer Microstructured High-Sensitive Ultrawide-Range Flexible Pressure Sensor With Modulus Gradient

• Published in: IEEE transactions on electron devices Vol. 69; no. 4; pp. 2030 - 2037
• Main Authors: Lu, Xiaozhou, Meng, Xiangyu, Shi, Yaoguang, Tang, Hongyao, Bao, Weimin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-04-2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Block copolymers; Butadiene; Carbon nanotubes; Contact resistance; Electric skin; Electrodes; Electronic devices; flexible pressure sensor; Graphene; high sensitivity; Microstructure; modulus gradient; multilayered structure; Multilayers; Piezoresistance; Polycaprolactone; Pressure distribution; Pressure sensors; Response time; Sensitivity; Sensors; Silver; ultrawide measurement range; Wearable technology
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2022.3154677

Flexible pressure sensors have been widely studied due to their potential applications in wearable electronics. However, the poor sensitivity and narrow working range seriously hinder their developments in practical applications. This article reports a flexible pressure sensor characterizing with modulus gradient and multilayered microstructure. The sensor has an ultrahigh sensitivity of 29.69 kPa −1 due to the gradient structure formed by low modulus Ag/hydrogenated styrene-butadiene block copolymer (SEBS) electrode layer and high modulus graphene (GR)/carbon nanotubes (CNTs)/polycaprolactone (PCL) composite with surface microstructure. The sensor has an ultrawide measurement range of 0-500 kPa due to its multilayered structure. In addition, the sensor has good linearity (4.85%) and repeatability (2.18%), rapid response time (50 and 30 ms), low detection limit (30 Pa), and long-term durability (1000 cycles). Experimental results suggest that the sensor can be used for effective detection of mechanical vibrations, pulse, and human motions and can also be used for measuring spatial pressure distribution after being arrayed. These applications indicate its great potential in wearable medical devices and electronic skins.