Boosting triboelectric performance of PDMS with dual-filler reinforcement for smart touch sensing

Smart touch sensing lies at the core of emerging technologies such as wearable electronics, human-machine interfaces, soft robotics, and interactive surfaces. Triboelectric nanogenerators (TENGs), which convert mechanical stimuli into electrical signals by contact electrification and electrostatic induction, have emerged as promising candidates for such touch-based sensing platforms. Polydimethylsiloxane (PDMS) is widely used in flexible electronics due to its mechanical flexibility, biocompatibility, and dielectric properties. However, its low dielectric constant and charge leakage limit its ability to store and separate charges, reducing the triboelectric performance. To address this challenge, we present a dual-filler reinforcement strategy to significantly boost the triboelectric output of PDMS by incorporating a dielectric filler (barium strontium titanate (BST)) and a conductive filler (graphite) into the PDMS matrix. Through this approach, we achieve synergistic effects that significantly improve surface charge density, dielectric constant, and charge trapping capability. Morphological, electrical, and mechanical characterizations demonstrate that the dual-filler approach leads to improved energy harvesting and touch sensing capabilities. This approach paves the way for high-performance, self-powered touch sensors with enhanced durability, making them ideal for applications in biomechanical monitoring and smart touch sensors.