Soft Robots with Brains of Rubber

The award for the strangest news today goes to … robots with no solid parts. Soft robots are cheaper, lighter, simpler to make, and safer for humans to bump into. We are not talking about padding around a solid frame, but robots made entirely of soft flexible squishy parts. This is possible very soon because the last necessarily solid part of a robot, the logic board or “brain,” has found a soft replacement.

It may sound impossible, but all of the logical calculations and processing now done by electronic computers can be accomplished mechanically with only rubber and air. How?

… researchers have built a soft computer using just rubber and air. “We’re emulating the thought process of an electronic computer, using only soft materials and pneumatic signals, replacing electronics with pressurized air,” says Daniel J. Preston, first author on a paper published in the Proceedings of the National Academy of Sciences and a postdoctoral researcher working with George Whitesides, the Woodford L. and Ann A. Flowers University Professor.

To make decisions, computers use digital logic gates, electronic circuits that receive messages (inputs) and determine reactions (outputs) based on their programming. Our circuitry isn’t so different: When a doctor strikes a tendon below our kneecap (input), the nervous system is programmed to jerk our leg (output).

Preston’s soft computer mimics this system using silicone tubing and pressurized air. To achieve the minimum types of logic gates required for complex operations — in this case, NOT, AND, and OR — he programmed the soft valves to react to different air pressures. For the NOT logic gate, for example, if the input is high pressure, the output will be low pressure. With these three logic gates, Preston says, “you could replicate any behavior found on any electronic computer.”

Soft robots could survive car accidents, floods, and could even function in nuclear disasters where high radiation would destroy solid robots. They can also be self-healing. Another advantage of Daniel J. Preston‘s micro pneumatic circuits is that they require zero power when not in use. As if this weren’t enough, they might even be given the power of invisibility:

… Depending on which material Preston selects, he could design a robot that is index-matched to a specific substance. So, if he chooses a material that camouflages in water, the robot would appear transparent when submerged.

Via SciDaily | Harvard

Are there elastomers transparent in air? It would seem so, since at least 1988.

Optically transparent, high-toughness elastomer using a polyrotaxane cross-linker as a molecular pulley

An elastomer is a three-dimensional network with a cross-linked polymer chain that undergoes large deformation with a small external force and returns to its original state when the external force is removed. Because of this hyperelasticity, elastomers are regarded as one of the best candidates for the matrix material of soft robots. 


High strength and optically transparent silicone rubber was prepared by two methods in this paper.

Via SciDirect (1988)

But transparency is just one option for invisibility, the new soft robots could also be designed to change colors dynamically to disappear against a surface like an octopus, according to this article on Forbes.

If the logic of a rubber micro pneumatic brain can be made to operate fast enough, this has potential to be the next computer revolution.

I’m reminded while reading this of a tiny wasp, that is so small, it supposedly could not function unless it’s brain cells were mechanical. A clockwork brain may already exist in this beneficial wasp used to control greenhouse whitefly pests.

A tiny wasp has brain cells so small, physics predicts they shouldn’t work at all. These miniature neurons might harbour subtle modifications, or they might work completely differently from all other known neurons – mechanically.

Read more at NewSci

As a bonus, the clockwork brained wasp has a name that sounds like a spell in a Harry Potter movie:

Encarsia formosa!

Anyway, if we can avoid disasters/wars that wipe out our current progress, a world of soft robots and quantum computers awaits future generations.

A final thought: about those grey aliens… What if they are made of rubber?

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