Breathable and Flexible Polymer Membranes with Mechanoresponsive Electrical Resistance
Flexible low-resistance membranes that tolerate very high deformability, produce low joule heating, and allow the passage of gases for human comfort are desired for wearable devices. Herein, a network of silver nanowires (AgNWs) between two highly porous electrospun thermoplastic polyurethane (TPU) membranes is presented. The membranes are mechanically robust (both for bending and stretching) and can withstand large strain before breakage (> 700%). The sheet resistance is as low as <0.1 Ω sq-1, and only increases to 1.6 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. This flexible, sandwich-like, electrically conductive membrane is a promising candidate for smart wearable devices and soft robotics.