Researchers have been working on ways to power robots for extended duration use. Long duration power for robots is a challenge because there is limited space inside most robots for batteries and other hardware. Scientists at Cornell have created a new synthetic vascular system for robots that can pump an energy-dense hydraulic liquid that stores energy, transmits force, and operates appendages while providing structure in a single integrated design.
The team says that soft robots are mostly fluid at up to 90% fluid per volume and often use a hydraulic liquid. Using that liquid to store energy until it is released in a chemical reduction and oxidation reaction, or redox reaction. Using that fluid to store energy offers the opportunity for increased energy density without added weight.
The team designed a soft aquatic robot that was inspired by a lionfish. The robot has a silicone skin on the outside and flexible electrodes and an ion separator membrane within to allow the robot to bend and flex. Interconnected zinc-iodide flow cell batteries power onboard pumps and electronics via electrochemical reactions.
The team says that using this system, they were able to achieve an energy density of about half of what a Tesla Model S lithium-ion battery produces. The robot they created swims using power transmitted to the fins from the pumping of the flow cell battery. The team says that their initial design had enough power to swim upstream for over 36 hours.
Soft robots like the concept the team created have the potential for underwater research and exploration. The robots do not need an exoskeleton or endoskeleton because they are supported by buoyancy. The soft robot that the researchers have created could lead to autonomous robots that roam the oceans on scientific missions and could potentially be sent to other planets for marine research.