Whether in construction or manufacturing, research or medicine, robots are generally known for their hardened steel structures. It?s considered a given that to construct a useful robot that could move with precision and handle specific tasks, one had to reach for at least a few rigid components.

Recently, though, researchers at Rutgers University reevaluated what materials are needed to make such a machine. In doing so, the team created a robot with a softer side.

Soft robotics, as the name implies, deals with robots created from materials that are decidedly flexible like rubber, cloth or plastic. Frequently, soft robot designs take their cues from nature, with features not unlike plant and animal appendages.

Dr. Aaron Mazzeo, assistant professor of mechanical and aerospace engineering at Rutgers, says there are specific advantages to using these types of materials. The lack of metal components is helpful where one might otherwise encounter problems with ?corrosion [in] sensitive environments or environments where you have electromagnetic waves.?

Those environments could also include chemically hostile landscapes that might weaken metals or prove fatal to humans – think hazmat sites or the surfaces of other planets.

Rutgers?s current model for the soft bot has endured drop tests from significant heights, can easily maneuver turns and will operate fully submerged in water, all of which makes rescue missions or oceanic research a possibility. Other soft robot designs might even prove helpful in surgical applications as the squishy features of the machine are more compatible with soft, organic tissues.

Even with the abundant advantages apparent in a soft robot, Mazzeo admits he had his doubts about the viability of the project, which required a ground-up rethinking of how they would achieve locomotion.

?I was honestly quite skeptical about the field,? remembers Mazzeo. ?I?m a mechanical engineer. We use alloys, we use bolts, we use nuts and screws to put things together.?

So when Mazzeo and his team set out to make a soft robot that could achieve rotary motion they had their work cut out for them. Thankfully ?students see what?s possible often when you don?t.?

Two particular students, Xiangyu Gong and Ke Yang, who both graduated with master?s degrees in mechanical engineering from Rutgers in 2015, hit upon the idea of incorporating peristalsis into a pneumatic winch that Mazzeo?s team had designed.

Peristalsis is a wave-like tightening and relaxing action that helps you swallow food. Mazzeo, Gong, Yang, and their team applied this motion to a series of small bladders that use pressurized gas to inflate and deflate in sequence, providing torque for their winch?s rotor. The winch is able to both raise or lower an object – and even brake – by simply holding a single inflation pattern.

Before long, Gong was asking whether their design would work to power a wheel. By placing the bladders directly inside a specially designed wheel body, the team succeeded in achieving the necessary force. This is an about-face from traditional design, eliminating the need for a rigid transmission system to provide power. Coupled with a custom silicone wheel, formed in a 3D printed mold, the system is a soft robotics breakthrough.

For now, Mazzeo and his team continue to improve upon their initial design, looking at ways to soften and integrate the robot rover?s power system, making it more autonomous. Mazzeo is also seeking funding for his team?s work, but is quick to acknowledge the immense support he?s received from his university.

?We?re doing things on the house,? says Mazzeo. ?So I?m very, very grateful to Rutgers for giving us the support we need and letting us continue to work on this research.?

by John Tolley