Mechanoluminescent-Perovskite Pressure Sensor for Structural Health Monitoring

Abstract

Here we report a highly sensitive and robust flexible thin film pressure sensor realized through the novel combination of mechanoluminescent (ML) material with perovskite. This thin film sensor is constructed through a low-cost and simple manufacturing technique. In this work, we adopted a lateral type design of a thin pressure sensor primarily consisting (i) a sensing layer of copper-doped zinc sulfide (ZnS:Cu)/polydimethylsiloxane (PDMS) composite and (ii) a light absorbing layer of perovskite. Atop the perovskite layer lies a thin Au layer acting as the electrodes. ZnS:Cu is one of the highest intensity light emitting material among all inorganic ML crystals. The ML intensity increases with the increase of applied pressure without requiring any irradiation for ML recovery, which indicates that the self-recovery of the ML in crystals takes place by trapping of drifting charge carriers in the presence of a piezoelectric field. As such, this crystal can be suitable for durable sensor material. In order to manufacture a stable sensor, a mixed halide perovskite is used as a light absorbing material. The electrical current of the pressure sensor increases with the increase of applied pressure. The sensor has the application in structural health monitoring of large composite structures. This work shows a novel approach to nextgeneration sensors and is a promising candidate for pressure sensitive applications