Highly Sensitive, Wearable, Durable Strain Sensors and Stretchable Conductors Using Graphene/Silicon Rubber Composites

TLDR

Wearable, durable strain sensors are essential for health monitoring, robotics, and human-machine interfaces, yet current fabrication methods are complex, low-sensitivity, and have limited service life. The study presents a facile, cost-effective, scalable method to develop high-performance strain sensors and stretchable conductors from a graphene platelet/silicon rubber composite film. The composite film is fabricated by coating graphene platelets with polydimethylsiloxane, creating a stretchable, robust structure that can be scaled up. The composite sensors exhibit linear, reproducible strain sensitivity with gauge factors ranging from 27.7 to 164.5, maintain consistent performance across fabrication batches, and are suitable for health monitoring, electronic skin, vibration sensing, and human-machine interface control.

Abstract

Highly sensitive, wearable and durable strain sensors are vital to the development of health monitoring systems, smart robots and human machine interfaces. The recent sensor fabrication progress is respectable, but it is limited by complexity, low sensitivity and unideal service life. Herein a facile, cost‐effective and scalable method is presented for the development of high‐performance strain sensors and stretchable conductors based on a composite film consisting of graphene platelets (GnPs) and silicon rubber. Through calculation by the tunneling theory using experimental data, the composite film has demonstrated ideal linear and reproducible sensitivity to tensile strains, which is contributed by the superior piezoresistivity of GnPs having tunable gauge factors 27.7–164.5. The composite sensors fabricated in different days demonstrate pretty similar performance, enabling applications as a health‐monitoring device to detect various human motions from finger bending to pulse. They can be used as electronic skin, a vibration sensor and a human‐machine interface controller. Stretchable conductors are made by coating and encapsulating GnPs with polydimethyl siloxane to create another composite; this structure allows the conductor to be readily bent and stretched with sufficient mechanical robustness and cyclability.