A soft matter computer for soft robots

Despite the growing interest in soft robotics, little attention has been paid to the development of soft matter computational mechanisms. Embedding computation directly into soft materials is not only necessary for the next generation of fully soft robots, but also for smart materials to move beyond stimulus-response relationships and towards the intelligent behaviours seen in biological systems. This article describes the Soft Matter Computer (SMC), a low-cost and easily fabricated computational mechanism for soft robots. The building block of an SMCis a conductive fluid receptor (CFR), which maps a fluidic input signal to an electrical output signal via electrodes embedded into a soft tube. SMCs can performboth analogue and digital computation. The potential of the SMC is demonstrated by integrating them into three soft robots: (i), a Softworm robot is controlled by an SMCwhich generates the control signals necessary for three distinct gaits; (ii), a soft gripper is given a set of reflexes which can be programmed by adjusting the parameters of the CFR; and (iii), a two degree of freedom bending actuator is switched between three distinct behaviours by varying only one input parameter. TheSoft Matter Computer is a low-cost way to integrate computation directly into soft materials, and an important step towards entirely soft autonomous robots.