Bean\nPod-Inspired Ultrasensitive and Self-Healing\nPressure Sensor Based on Laser-Induced Graphene and Polystyrene Microsphere\nSandwiched Structure

Abstract

Flexible pressure\nsensors are currently at the center stage of\nwearable electronics. Despite tremendous progress in the recent years, flexible pressure sensors with\nhigh sensitivity, high stability, and mechanical robustness are still\nchallenging. In this paper, as inspired by the bean pod structure,\na sensor architecture consisting a microspacer core layer of polystyrene\n(PS) microspheres, sandwiched between two laser-induced graphene/polyurethane\n(LIG/PU) films, is presented. A flexible and self-healable pressure\nsensor is prepared, achieving ultrahigh sensitivity, improved linearity,\nwide sensing range up to 100 kPa, and excellent stability (for over\n1000 loading–unloading cycles). Specifically, the pressure\nsensor achieves high sensitivities of 149, 659, and 2048 kPa^–1 for the pressure ranges of 0–1, 1–10, and 10–100\nkPa, respectively. Upon three cut–heal cycles at room temperature,\nseverely damaged devices are self-healed and are able to maintain\nhigh sensitivity. The sensors have been further verified in stringent\napplications, such as human arterial pulse monitoring and gait detection.\nThe novel device architecture enabling facile fabrication and high\nperformance paves the way to the scalable production of pressure sensors\nfor human physiological diagnostics and other advanced wearable applications.