An autonomous untethered fast soft robotic insect driven by low-voltage dielectric elastomer actuators

Abstract

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 subgram 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 kilohertz operation with high power density but require typically several kilovolts to reach full strain. The mass of kilovolt supplies has limited DEA robot speed and performance. In this work, we report low-voltage stacked DEAs (LVSDEAs) with an operating voltage below 450 volts and used them to propel an insect-sized (40 millimeters long) soft untethered and autonomous legged robot. The DEAnsect body, with three LVSDEAs to drive its three legs, weighs 190 milligrams and can carry a 950-milligram payload (five times its body weight). The unloaded DEAnsect moves at 30 millimeters/second and is very robust by virtue of its compliance. The sub–500-volt operation voltage enabled us to develop 780-milligram drive electronics, including optical sensors, a microcontroller, and a battery, for two channels to output 450 volts with frequencies up to 1 kilohertz. By integrating this flexible printed circuit board with the DEAnsect, we developed a subgram robot capable of autonomous navigation, independently following printed paths. This work paves the way for new generations of resilient soft and fast untethered robots.

Multimode Hydraulically Amplified Electrostatic Actuators for Wearable Haptics

“…Their size and shape could be adapted to each body part to provide an electrically controlled, lightweight, full‐body haptic suit. By reducing film thicknesses and using different materials, we plan to reduce the drive voltage to below 500 V, a value below which compact electronics are much easier to manufacture; for example, Ji et al [ 44 ] reported 350 mg two‐channel 500 V circuits for untethered mobile robots.…”

A Unidirectional Soft Dielectric Elastomer Actuator Enabled by Built-In Honeycomb Metastructures

“…Another significant concern is that the requirement for high voltage could hinder the proposed actuator for practical applications. It is noticed that, recently, Ji et al have largely addressed this issue by fabricating stacked ultrathin DE membranes, powered by a low voltage of 450 V [46]. They clarified that below 500 V, there exists a vast selection of low-mass, miniature, commodity surface-mount components, enabling complex kilohertz voltage sources weighing only tens or hundreds of milligrams to be integrated into soft robotic systems.…”

Untethered Feel‐Through Haptics Using 18‐µm Thick Dielectric Elastomer Actuators

“…These electrodes add nearly negligible stiffness to the elastomer, and have a low enough resistance to allow operation at several hundred Hz. [46] Two versions of FT haptic devices are presented here ( Figure 1). The first version uses a flexible frame (Figure 1a,b) to maintain the DEA pre-stretch and to facilitate the electrical connection between the DEA electrodes and very thin wires.…”