Mechanoluminescent-energy harvesting bimodal sensors for self-powered communication sensors

Mechanoluminescence (ML) is the emission of light triggered by mechanical stress. In the meantime, accurate, quantitative force measurement is made possible by piezoelectricity, which transforms mechanical deformation into electrical signals. A deep insight into the mechanical interactions, such as strain-based phenomena, is achieved by integrating ML and piezoelectricity into a single device. In this study, a composite based on ZnS:Cu–polydimethylsiloxane (PDMS) is developed to achieve this dual functionality for ML-based optical responses and piezoelectric-based electrical output. The presence of piezoelectricity in PDMS–ZnS:Cu composites was traced using piezo force microscopy (PFM) imaging. Various mechanical stimuli of pressing, stretching, and bending are applied to evaluate the performance of the device. Under a force of 5 N, the piezoelectric nanogenerator (PENG) device generates a voltage of 17 V and a current of 70 nA. Additionally, ML and PENG effects are employed for underwater communications. A signal processing technique is further utilized for the classification of voltage signals produced during underwater communications. This self-powered dual-mode sensor has great potential for use in energy harvesting, wearable technology, and battery-free systems, opening the door to more intelligent and responsive user interfaces.