A High-Pressure Sensor\nBased on a Thermoplastic Polyester\nElastomer with High Sensitivity and Wide Detection Range

Flexible pressure sensors demonstrate substantial potential\nin\nhealth monitoring, human–computer interactions, and intelligent\nhome applications. However, developing piezoresistive foam sensors\nwith high sensitivity in high-pressure ranges, crucial for detecting\nplantar movement and aiding in sports injury recovery, poses significant\nchallenges. Herein, we propose a facile and environmentally friendly\nmethod for fabricating thermoplastic polyester elastomer (TPEE)/carbon\nnanostructure (CNS) foam pressure sensors with segregated and microcellular\nstructures. The CNS was selectively distributed at the interfaces\nof the TPEE regions, minimizing its impact on the foaming behavior\nand mechanical properties of the TPEE matrix. Benefiting from the\nmacroscopically segregated structure, the TPEE/CNS foams exhibited\ngood electrical conductivity with low CNS content, achieving an ultralow\npercolation threshold of 0.02 wt %. Additionally, the sensitivity\nof the TPEE/CNS foam sensors could be adjusted by varying the CNS\ncontent and expansion ratio. The TPEE/CNS foam sensor with a CNS content\nof 0.2 wt % demonstrated a high sensitivity of 0.67 kPa<sup>–1</sup> in the high-pressure range of 212–858 kPa, long-term durability\n(5000 cycles), and a rapid response time of 200 ms. Furthermore, it\neffectively detected various physical activities, such as grip strength,\ndumbbells, and different walking conditions. Consequently, this sensor\noffers promising applications in smart fitness equipment, protective\npads, intelligent shoe soles, and other high-pressure sensing environments.