PEDOT: PSS/GO–TPU Threaded Flexible Strain Sensor with High Sensitivity and a Broad Detection Range for Versatile Sensing Applications

Enhancing the sensitivity, sensing range, durability, and shaping characteristics of flexible strain sensors remains a challenge. Herein, we present a poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT: PSS)/graphene oxide (GO)–thermoplastic polyurethane (TPU) threaded flexible strain sensor fabricated via a wet spinning process. The TPU thread serves as an elastic skeleton, while PEDOT: PSS/GO nanohybrids are doped into the thread substrate. The properties of the nanohybrids enable the sensor to achieve both mechanical attributes and piezoresistive characteristics. The sensor exhibits a tensile strength of 10.16 MPa, great sensitivity (gauge factor up to 165 at 300–420% strain and 10.9 at 0–300% strain), a wide sensing range (up to 420% strain), rapid response time (80 ms), and excellent durability and repeatability (>6000 cycles). It can be readily mounted into a glove or mask, or directly attached to human skin to monitor human motion, pulse, respiration rate, etc. It was also applied to detect the dimensional changes of a balloon and an in vitro lung model during inflation and deflation. A 5 × 5 sensing array was constructed for spatial pressure mapping and shape recognition. Test results demonstrate the potential of the proposed strain sensors as candidates for wearable electronics in health monitoring and human-computer interaction.