1, Yale University, New Haven, Connecticut, United States
Soft robotics is evolving from its nascent form of rubber-based inflatables into complex robotic architectures from which industry can draw to develop new and improved methods of human-machine interaction. Through this evolutionary process, stiffness changing materials have emerged as a key facet of creating systems that can enable move-and-hold operations, while still permitting the soft body manipulation prevalent in traditional soft robotics. Though many approaches have been taken towards stiffness-on-demand, here we focus on improving the localization of stiffness change in thermally responsive materials that undergo stiffness changes when heated above a specified temperature. In this talk we present a flexible, stretchable silicone composite material that, when combined with liquid metal electrodes, can create 2D localized high-temperature regions that soften a neighboring thermally responsive material. We use this system to create artificial hinges that allow for targeted shape change, in both 1 and 2 dimensions, enabling the folding of a rigid material system into complex, shape-holding structures. We also demonstrate the capability of bonding the silicone composite to the stiffness-changing material in order to provide resettable shape-change.