Toward Programmable Materials for Wearable Electronics: Electrical Welding Turns Sensors into Conductors

Stretchable electrical conductors and stretchable strain sensors are two key components in applications such as soft robotics, artificial soft skins, and wearable electronics. Very different approaches are usually implemented to design either conductors or sensors. Here, transformation of an electrically conductive material from a sensor to a conductor using electrical welding (e-welding) is proposed. This method is demonstrated in the case of a thermoplastic polymer sponge decorated with silver nanowires. The sensor-like behavior of the sponge is programmed by e-welding into conductor-like behavior, i.e., suppressing the gauge factor by 86%, without varying the density of the silver nanowires. An application of e-welding in the fabrication of a sensor-conductor hybrid material that may be applied as soft artificial skin in robotics is demonstrated.