Breathable and Flexible Polymer Membranes with Mechanoresponsive Electric Resistance
This work is about sandwiching a network of silver nanowires (AgNWs) between two highly porous electrospun thermoplastic polyurethane (TPU) membranes. The membranes are mechanically robust (both for bending and stretching) with a strong interface and large strain before breakage (more than 700%). The sheet resistance is as low as <0.1 (±0.01) Ω sq−1, and changed to only 1.6 (±0.43) Ω sq−1 upon stretching to 100% strain. The combination of polymer elasticity and the AgNW network structure provides a reversible change in resistance beyond 100% strain. A detailed thermographic analysis is employed to in situ image and characterize the AgNW network morphology during various stretched conditions. It is believed that this flexible, sandwich‐like, electrically conductive membrane is a good candidate for smart wearable devices and soft robots.