Shape Memory Silicone Using Phase-Changing Inclusions

Functional, responsive materials are attractive for use as key components in soft robots as they can replace otherwise rigid or bulky parts. In this work, we present a functional silicone with shape memory properties that, due to the retention of elasticity and flexibility, can be seamlessly integrated into the body of a soft robot. By dispersing particles of low-melting-point metal alloy (Field's metal) into a silicone matrix, the resulting composite can be “frozen” into various shapes by sequentially heating to melt the Field's metal particles, stretching the composite, and cooling to solidify the Field's metal particles in the deformed configuration. The ramifications of this operational capability include both stiffness control and 3D shape reconfiguration. In this paper, we characterize the thermomechanical behavior and shape memory performance of the Field's metal/silicone composite. We then highlight applications of the material to impedance and trajectory control, and topography recording.