High-Sensitivity ZnS:Cu Piezoresistive Sensor for Underwater Visual Sensing.

In recent years, flexible wearable sensors have been used for human motion monitoring and human-computer interaction, but designing a sensitive, multifunctional composite sensor adaptable to complex scenarios remains challenging. In this work, we developed a multifunctional composite sensor in a multilayer design by combining highly conductive multiwalled carbon nanotubes (MWCNTs) and graphite (GP) with nanoluminescent materials ZnS:Cu to achieve visual feedback and signal detection. Through material optimization, we developed a sensor with stable luminescence (I_{ML(300 Cycle)} = 90%I₀) and high sensitivity (GF = 13.65), enabling reliable signal detection in complex scenarios. Leveraging its strong luminescence and durability, a low-light gesture recognition system was built, effectively addressing recognition challenges and providing intuitive visual support. In addition, we apply the trained classifier model to unmanned vehicle control in low light, which further verifies the feasibility of the materials and algorithms. Finally, as a proof of concept, the multifunctional composite sensor is designed for real-time sensing in deep-sea exploration, rescue, and low-light underwater communication, demonstrating great potential for wearable devices.