Flexible Temperature Sensor with Wide Sensing Range and Fast Response Enabled by PEDOT:PSS/CNT and Thermal Management Encapsulation

Abstract

Flexible temperature sensors have attracted widespread attention due to their potential in diverse applications, including medical health, intelligent robots, and industrial production. However, most flexible temperature sensors work in a narrow temperature range and exhibit relatively long response times. Herein, we present a flexible temperature sensor with a wide sensing range and fast response characteristics. The PEDOT:PSS/CNT-based sensitive material exhibits excellent rheological and sensing properties, enabling wide-range temperature sensing and fabrication through a simple screen-printing process. To achieve a fast response, an innovative thermal management method that combines the thermal conductive layer and the thermal insulation layer on both sides of the sensing layer is employed. The thermally conductive composite PDMS/flake graphite and thermal insulation composite PDMS/hollow glass microsphere are formulated to offer satisfactory thermal and mechanical properties. As a result, the developed sensor possesses a wide sensing range of −30 to 90 °C, a high linearity of 0.996, and a fast response to temperature. The sensor also demonstrates excellent stability, including low hysteresis (4.7%), high repeatability (1000 cycles), long operational lifespan (90 days), and resistance to pressure and bending. Application experiments of robotic object grasping and human respiratory monitoring show that the sensor can accurately measure the temperatures of various objects and clearly record the fast temperature changes throughout the entire breathing process, which indicates its promising potential for applications in robotic manipulation and human health monitoring.