A High-Pressure Sensor Based on a Thermoplastic Polyester Elastomer with High Sensitivity and Wide Detection Range

Flexible pressure sensors demonstrate substantial potential in health monitoring, human–computer interactions, and intelligent home applications. However, developing piezoresistive foam sensors with high sensitivity in high-pressure ranges, crucial for detecting plantar movement and aiding in sports injury recovery, poses significant challenges. Herein, we propose a facile and environmentally friendly method for fabricating thermoplastic polyester elastomer (TPEE)/carbon nanostructure (CNS) foam pressure sensors with segregated and microcellular structures. The CNS was selectively distributed at the interfaces of the TPEE regions, minimizing its impact on the foaming behavior and mechanical properties of the TPEE matrix. Benefiting from the macroscopically segregated structure, the TPEE/CNS foams exhibited good electrical conductivity with low CNS content, achieving an ultralow percolation threshold of 0.02 wt %. Additionally, the sensitivity of the TPEE/CNS foam sensors could be adjusted by varying the CNS content and expansion ratio. The TPEE/CNS foam sensor with a CNS content of 0.2 wt % demonstrated a high sensitivity of 0.67 kPa–1 in the high-pressure range of 212–858 kPa, long-term durability (5000 cycles), and a rapid response time of 200 ms. Furthermore, it effectively detected various physical activities, such as grip strength, dumbbells, and different walking conditions. Consequently, this sensor offers promising applications in smart fitness equipment, protective pads, intelligent shoe soles, and other high-pressure sensing environments.