Soft Robot Swarms

Compared to traditional rigid systems, soft robots have the potential to be robust, cheap, versatile, and able to navigate in unpredictable environments and confined spaces. These are all features that would lend themselves well to a robot swarm. 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. Furthermore, few soft actuators are able to carry large payloads, or tune their rigidity when the circumstances require it. Finally, there is still a need for better proprioceptive soft sensors to enable stand-alone soft robots. The following text describes our efforts to address these shortcomings, with the eventual goal of creating soft robot swarms.

Touch Sensitive Soft Robots for Viticulture

Manual assessment of crops is time consuming, labor intensive, and difficult to perform well over large areas. Additionally, the U.S. is facing a tremendous worker shortage in agriculture, prompting increased research on agricultural automation. Despite the promise of sensor networks and computer vision, technological advances have yet to deliver reliable and accurate crop assessment in scenarios where lighting is poor and in the presence of frequent foliage occlusions.

Our research applies inexpensive robots that can augment vision techniques with soft touch sensitive manipulators for careful assessment of fragile agricultural products, specifically grapes.

This work is funded by the Cornell Digital Agriculture Research Initiative and the National Institute of Food and Agriculture 2017-2020.

Elastomer Actuators with Granular Fluids

As random as it sounds, popcorn kernels are a natural, edible, and inexpensive material that has the potential to rapidly expand with high force upon application of heat. Although this transition is irreversible, it carries potential for several robotic applications including jamming and edible robotics. We have characterized a range of properties and shown proof-of-concept implementations with origami-, rigid-, and strain limited silicone grippers.

Paper is under review.

Inflated DEA Elastomer Actuators
Soft Actuator

We have shown that dielectric elastomer actuators can be used to push inflated hyperelastic membranes past snap-through instabilities to create large stable deformations. By coupling multiple such membranes, it 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 are exploring untethered soft systems where large displacements, low energy consumption, small scale, light weight, and low complexity are needed; as well as integration of these actuators into foldable robots.

Publications

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.

L. Hines, K. Petersen, and M. Sitti. “Asymmetric Stable States in Inflated Dielectric Elastomer Actuators”. IEEE International Conference on Robotics and Automation (ICRA), Singapore, 2017.