Dual-Mode Stretchable Sensor Array with Integrated Capacitive and Mechanoluminescent Sensor Unit for Static and Dynamic Strain Mapping

Abstract

Electronic skin (e-skin) has the potential to detect large-scale strain, which is typically achieved by integrating multiple strain sensors into an array. However, the latency and limited resolution of sensing have hindered its large-scale sensing applications. Here, we have developed a high-resolution detection sensing system capable of detecting static and dynamic strain with a simple fabrication process by combining capacitive and mechanoluminescent (ML) sensor units. An elastic polydimethylsiloxane (PDMS) composite film doped with ZnS:Cu and BaTiO3(BT) particles are fabricated as the functional film of the capacitive sensor. In contrast, the transparent electrode was fabricated on the surface of the as-prepared film. By incorporating BT nanoparticles into the elastic substrate, the ML intensity of the ZnS:Cu was improved up to 2.89 times that without BT addition, and the sensitivity of the capacitive sensor was increased as well. The capacitive part of the sensor presented a GF of 0.9 and good stability, while the ML part exhibited excellent performance, making it suitable for both static and dynamic sensing. Furthermore, the strain sensor integrated by 10 × 10 sensing units is demonstrated to detect large-scale strain with high resolution. Moreover, finger joint strain distribution tracking is achieved by attaching the strain sensor unit to the finger joint. With these characteristics, the e-skin may have great potential for bio-motion monitoring and human-computer interaction applications.