A Venus Fly Trap is an efficient machine that waits. The carnivorous plant, beloved of horror fans and elementary schoolers alike, is partial inspiration for a new category of robotic building material. Informed by and seeking to emulate the elasticity of living organisms, researchers at Purdue University have developed a new kind of soft robotic actuator. With further development, these actuators could shape industrial and battlefield robotics.
The research, “Elastic Energy Storage Enables Rapid and Programmable Actuation in Soft Machines,” published October 25, 2019, in Advanced Functional Materials, detail both how controllable elastic materials can be made, and how that design can shape a whole category of bio-inspired robots. The “bio” in this case in particularly broad, with everything from chameleon tongues to frog hands to the clasping mechanism of Venus Fly Traps contributing to the look into elastic storage of energy.
While it’s easy to imagine a use for these machines in motion, one of the most valuable benefits from such soft actuators is how they allow a robot to remain effortlessly in place. Inspired by how birds like woodpeckers cling to trees, the researchers tested the grip of the actuators at difficult angles.
“The elastic energy that [prestressed soft actuators] store in their prestressed elastomeric layer enables the fabrication of grippers capable of zero‐power holding up to 100 times their weight and perching upside down from angles of up to 116 [degrees],” write the paper’s authors.
For platforms that want to remain in place as much as they want to move, the option to simply grab onto a branch and hold on would be a boon. Easy to imagine such systems, sipping on power as they record and transmit data, flying into a forest and then providing an ambient awareness while saving battery power for a return flight.
As with all academic developments in robotic technology, what is most interesting to military planners and designers is the potential. Soft robotic actuators, controlled remotely or set up to respond autonomously to signals from sensors, could facilitate everything from drone landing to anti-vehicle traps to simply more useful tools on an assembly line.
What is perhaps most intriguing is the ability, demonstrated on video, of a robot to lash out and catch a living beetle before it can even sense it is in peril. With speed at a premium on the battlefield of tomorrow, there’s almost certainly a use for a robot that can not just sense but act in the blink of a second.
Watch a video about the prestressed soft actuators below: