Ultrasensitive and self-alarm pressure sensor based on laser-induced graphene and sea urchin-shaped Fe2O3 sandwiched structure

Abstract

Flexible pressure sensors are widely used in wearable electronics. In recent years, it is still a challenge to prepare high-sensitivity and high-performance pressure sensors, though flexible pressure sensors have made significant progress. Therefore, a new sensor structure is designed in this study. This structure is composed of sea urchin-like Fe2O3 as a spacer layer, which is sandwiched between two laser-induced graphene (LIG)/polyimide (PI) films. Additionally, a flexible multifunctional sensing device with both health monitoring and alarm functions is prepared based on the excellent mechanical properties and thermal conductivity of LIG. Multifunctional sensing devices have high sensitivity, integrated monitoring, and alarm functions. Specifically, the sensitivity of the pressure sensor is 603 kPa−1 for the pressure ranges of 0–10 kPa. The pressure sensor possesses a working range of up to 200 kPa and good cycle stability (for over 3000 loading–unloading cycles). Furthermore, LIG is employed as a heater to realize the alarm function. In this work, the combination of high performance and simple methods provides an effective method for the development of the integration of multifunctional pressure sensors for wearable electronic devices.