Soft Robot Actuators

Soft Actuator

Compared to traditional rigid systems, soft robots have the potential to be robust, cheap, versatile, and able to navigate the tight spaces of a messy construction site. Currently, however, the majority of soft systems exploit air- or fluid-filled flexible chambers restricting them to the use of compressors or pumps through tethers or bulky payloads.


We have developed a soft actuation methodology to enable small-scale untethered soft robots. The idea is based on how dielectric elastomer actuators can be used to push inflated hyperelastic membranes past snap-through instabilities to create large stable deformations. In contrast to prior work, by coupling multiple such membranes, we have shown that is possible to make this deformation reversible and repeatable in a sealed pressurized chamber. The actuator is not only capable of switching back and forth between multiple stable states, but has a number of stable states proportional to the number of actuatable membranes in the chamber. This project started in the Physical Intelligence Department at the Max Planck for Intelligent Systems 2014-1016.

Building on this actuator methodology, we will explore untethered soft systems where large displacements, low energy consumption, small scale, light weight, and low complexity are needed.


L. Hines*, K. Petersen*, and M. Sitti. Inflated Soft Actuators with Reversible Stable Deformations. Communication Advanced Materials. 10.1002/adma.201600107, 2016. *Equally contributing authors.