An autonomous untethered soft robotic insect

Insects are a constant source of inspiration for roboticists. Their compliant bodies allow them to squeeze through small openings and be highly resilient to impacts. However, making sub-gram autonomous soft robots, untethered and capable of responding intelligently to the environment, is a long-standing challenge. One obstacle is the low power density of soft actuators, leading to small robots unable to carry their sense and control electronics and a power supply. Dielectric Elastomer Actuators (DEAs), a class of electrostatic electroactive polymers, allow for kHz operation with high power density, but require typically several kV to reach full strain. The mass of kV supplies has limited DEA robot speed and performance. In this work, we report Low-Voltage Stacked Dielectric Elastomer Actuators (LVSDEAs) with an operating voltage below 450V, and use them to propel an insect-sized (40 mm long) soft untethered and autonomous legged robot. The DEAnsect body, with 3 LVSDEAs to drive its three legs, weighs 190 mg and can carry a 950 mg payload (5x its body weight). The unloaded DEAnsect moves at 30 mm/s and is very robust by virtue of its compliance. The sub-500V operation voltage enabled us to develop 780 mg drive electronics, including optical sensors, a microcontroller and a battery, for 2 channels to output 450V with frequencies up to 1 kHz. By integrating this flexible PCB with the DEAnsect, we developed a sub-gram robot capable of autonomous navigation, independently following printed paths. This work paves the way for new generations of resilient soft and fast untethered robots.