Response Regulation for Epidermal Fabric Strain Sensors via Mechanical Strategy

Advances in fabric strain sensors have established a route to comfortable-to-wear flexible electronics with particularly remarkable permeability and low modulus due to their porous fabric microstructure. A key challenge that remains unsolved is to regulate the sensor response via on-demand design for a variety of application scenarios to sufficiently exploit the highest possible sensitivity. While recent reports have described a variety of options in varying the material and orientation of the overall fiber mat, the development of approaches where multiple sensors with different responses can be integrated on a single substrate without affecting macroscopic mechanical properties remains an area of continued interest. Herein, a simple mechanical strategy is reported, which plates the patterned functional material on the fabric mat at a pre-stretched state in the prescribed direction, and control of direction and prestrain forms either sensors with different responses or strain-insensitive interconnects. A systematic study has revealed the underlying mechanism of this strategy, which can serve as a guideline for the on-demand design and fabrication of fabric strain sensors. Demonstration applications in motion monitoring bandages and gesture recognition gloves illustrate capabilities in functional epidermal sensing devices.