Cornell University researchers have developed a system of circulating liquid - "robot blood" within robotic structures to store energy and power robotic applications for sophisticated, long-duration tasks.
Creating a synthetic vascular capable of pumping energy-dense hydraulic liquid that stores energy, the system they created can also transmit force, operates appendages, and provides structure, all in an integrated design.
An associate professor of mechanical and aerospace engineering at Cornell, Rob Shepherd, said that in nature, it is possible to see how long organisms can perform while doing sophisticated tasks. Robots can't operate similar feats for quite long. The researchers published the work in Nature.
To test the concept, the team created a soft aquatic robot inspired by a lionfish, designed by the co-author of the study, James Pikul, a former post-doctoral researcher, now an assistant professor at the University of Pennsylvania. Lionfish use undulating fanlike fins to glide through coral-reef environments.
The robot can bend and flex through the silicone skin on the outside with flexible electrodes and an ion separator membrane within. Interconnected zinc-iodide flow cell batteries power onboard pumps and electronic through electrochemical reactions. The researchers achieved energy density equal to about half that of a Tesla Model S lithium-ion battery. The robot swims with the use of power transmitted to the fins from the pumping of the flow cell battery. The initial design provided enough energy to swim upstream for more than 36 hours.
Underwater soft robots provide fantastic possibilities for the researchers and exploration. Since buoyancy supports soft aquatic robots, they don't require an exoskeleton or endoskeleton to maintain the structure. By designing power sources that give robots the ability to function for more extended periods, Shepherd thinks autonomous robots could soon be roaming the Earth's oceans on vital scientific missions and for delicate environmental tasks like sampling coral reefs. Also, these devices could be sent to extraterrestrial worlds for underwater reconnaissance missions.
The Office of Naval Research supported the work and co-authors of the study include Lynden Archer, the James A. Friend Distinguished Professor of Engineering in the Smith School of Chemical and Biomolecular Engineering: Snehashis Choudhury, currently post-doctoral research at Stanford; and doctoral candidate Rhiannon Jerch. The director of the Organic Robotics Lab, Shepherd is senior author of "Electrolytic Vascular Systems for Energy Dense Robots," with doctoral student Cameron Aubin as the lead author of the project.
