Paving the way for humanlike robots, the researchers at Columbia University have created synthetic soft muscles that are able to lift 1,000 times their own weight. Dubbed soft actuator, these artificial muscles have been created using 3D printing technique. They can push, pull, twist, bend and lift weight and cost just US$ 0.03/gram to make.

Most soft robots developed so far by researchers rely on some bulky hydraulic or pneumatic system for power. Usually, the movements in these robots are controlled through bladders filled with some liquid or gas. Since these robots require large external components for power, they can’t be used in real-world environments.

The synthetic muscles created by Columbia University researchers are being claimed to be three times more powerful than their natural counterparts. They have intrinsic expansion ability, which means they don’t need any external component, like external pumps or high voltage converters, to expand or contract. They are made of a silicone rubber matrix which is pocketed with ethanol. These two materials give these muscles high elasticity and low density. To make these synthetic muscles expand, one has to give a low voltage to the muscle using a resistive wire that is embedded inside. This small amount of electricity causes the ethanol in the micro-pockets to boil, which results in expansion of the silicon matrix.

According to researchers, the strain density (expansion/gram) of these muscles is 15 times that of the natural muscles. The experimental tests carried out on these muscles revealed that they can expand by up to 900 percent when heated to 176ºF (80ºC) using 8 volts of electricity. A big advantage of these soft muscles is that they can be shaped and reshaped in a variety of ways.

Researchers believe their new invention could revolutionize the development of soft and soft-hard robots, which would be used to get assistance in disaster management, healthcare, and a variety of other applications where manipulation and gripping is required.

The team is now planning to add sensing capabilities to these artificial muscles. Researchers also want to replace the resistive wires inside the muscle with an embedded conductive material. There are also plans to use artificial intelligence with these muscles to allow better control over them.

This project was partly funded by the Israeli defense ministry. The detailed findings of the study were published in the journal Nature Communications.