Flexible Stretchable Mechanoluminescent- Perovskite Sensor for Structural Health Monitoring

Abstract

Previously, we reported a flexible thin-film sensor realized through the combination of mechanoluminescent (ML) material with perovskite, which consists of multiple layers to harvest ML light. In this work, a thin film stretchable sensor is constructed through a simple manufacturing technique. The sensor comprises a thin functional layer of copper-doped zinc sulfide (ZnS:Cu) as a light emitter and a thin perovskite layer as a light absorber. The perovskite layer is constructed on a thin layer of poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), which is developed on a stretchable polydimethylsiloxane (PDMS) substrate. Atop the thin perovskite lies a thin eutectic gallium indium (EGaIn) layer acting as an electrode. The simple selfpowered stretchable sensor allows easy fabrication and is a non-complex sensor architecture. Here, ZnS:Cu emits lights and perovskite immediately absorbs the light and converts it to electrical current. The output current of the sensor increases with an increase of applied strain. The self-powered sensor may find many applications in foot ulcer detection, prosthetic/artificial electronic skins, touchpad, and structural health monitoring of large composite structures.