Soft Robots, when inspiration comes from everyday life

Recently, we told you about “ fluid ” robotic devices capable of having a certain autonomy, falling into the category of soft robots. One of their main stumbling blocks, however, was the battery life which, although record-breaking, still limited the use of the equipment. In addition to this , the ultimate dream of the designers is a robot that not only moves by itself, but also reacts to the surrounding environment .

This is what the researchers of the Eindhoven University of Technology (TU / e) thought of, who found inspiration from a rather common component of everyday life.

Soft robots – the unusual insight from a common object

One of the scientists leading the project says:

We want to create robots without a central computer, which move and react to the surrounding environment thanks to reflections incorporated in themselves.

Bas Overvelde

In Matter magazine, his team presents a robot that works thanks to air pressure (without electronic components) . Moreover – here the peculiarity – it walks and changes pace responding to the environment thanks to a valve designed ad hoc .

Called a “hysteretic valve” in the publication in Matter magazine, it could be mistaken for a variation of the opening of a bottle of ketchup . This ensures that the contents of the bottle come out normally, without excess, so that it can be dosed properly. But sometimes the ketchup splatters if someone holds it upside down and crushes it hard. And it is precisely this unwanted inconvenience that prompted Overvelde and colleagues to use the same phenomenon to make a robot move.

Realization, characteristics and first devices

Using the computer, the researchers first performed simulations by designing properties such as the stiffness of the small flaps in the valve opening. They then built the actual object out of silicone rubber, using 3D printed shapes. Finally, to create an initially closed valve, they engraved small notches using a laser; in this way, it opens suddenly when the pressure is high enough, closing only when the pressure drops a little.

After the realization, the team connected the valve to a pump and a tank by rhythmically increasing the pressure and passage of the air. And here the soft robot moves its artificial muscles by inflating and relaxing them alternately!

Other experiments, again using the computer, have led to the creation of a four-legged robot with a natural walking rhythm, without external commands . In fact, as another researcher says: two valves of this type connected to the same tank, seemed to move in alternating directions in a very precise way. A completely unexpected thing, but which turned out to be actually working.
A flexible hand that reacted rhythmically was also made through the same process.

The new frontiers of soft robotics

To date, robots are still mainly associated with mechanical "iron" apparatuses, controlled by a central computer that has to think about every step. Living beings, on the other hand, move fluidly because their behavior is embedded in their own body; which is also ideal for robots that constantly interact with people , such as in medical care. The research field of soft robots therefore works with soft and flexible materials that respond to changes in their environment without external control.

Soft robots

In this sense, thanks to the new results obtained, the researchers state that it is possible to replicate complex behavior with simple parts. Without a computer that programs every move.
But there is the other advantage that we have already talked about. A robot that moves thanks to built-in natural reflections not only saves computing power, but also energy . In living creatures, many movements and behaviors are noted to result from the construction of the body and the mechanics of the muscles. And this seems to be independent of the commands of the brain.

Thus, the direction taken by Overvelde and his team seems clear: towards more autonomous, simple and automatically responding soft robots to environmental stimuli.

The Soft Robots article, when the inspiration comes from the newspaper was written on: Tech CuE | Close-up Engineering .