New robotic tissue expands up to 900% and is three times stronger than muscle

By Warren Miller, contributing writer

One of the biggest remaining hurdles in developing robots that can simulate human movement may have just been crossed. Researchers at Columbia University’s School of Engineering and Applied Science have created a synthetic tissue analogous to human muscle and that can lift up to 1,000 times its own weight. More importantly, the tissue doesn’t need to be connected to elaborate equipment in order to expand and contract, meaning that it could allow robots to move around autonomously without being tethered to a confined area. 

Soft robotics, or the field of robotics designed to closely replicate human movement, has almost unlimited potential in the areas of health care and manufacturing. Until this breakthrough, however, most soft robots weren’t able to move very far away from the machines that supported them. The technologies they used as analogs to human muscles typically involved elastomer skins inflated (and deflated) with a liquid or pressurized gas to mimic muscular contraction and extension. That approach required compressors, regulators, and other bulky equipment unsuited to miniaturization, forcing the robots to be tethered to the systems that powered their “muscles,” thereby restricting their freedom of movement.

This breakthrough voids such restrictions. According to Hod Lipson, the lead scientist on the Columbia project, their 3D-printable synthetic tissue is thus a significant development in the area of physical robot construction. “We’ve been making great strides toward making robot minds, but robot bodies are still primitive,” said Lipson. “This is a big piece of the puzzle and, like biology, the new actuator can be shaped and reshaped a thousand ways. We’ve overcome one of the final barriers to making life-like robots.” A video of the tissue in action shows what can be achieved.

The new robotic tissue’s strain density (expansion per gram) is 15 times greater than natural muscle tissue, allowing it to expand up to 900% by simply heating the tissue up to 80°C. Tests, reported in the journal Nature Communications, showed that six grams of the material could lift more than six kilograms of weight. In their studies, the researchers used a thin, resistive wire to conduct only 8 volts of electricity to perform the heating. In the future, they hope to be able to use conducive materials to replace the wire altogether, theoretically making robots outfitted with the tissue completely autonomous and able to carry objects across rooms, down corridors, or right to your doorstep.

Image source: Pixabay.

This breakthrough may also eventually allow robots to be sized appropriate to the task. Small robots that can operate off of battery power (or perhaps even power harvested from the environment) could accomplish many tasks that larger robots can’t. Maintenance or surveys of large structures — think bridges, airplanes, ships, or skyscrapers — might best be accomplished by small robots that can climb right on a structure and report back any defects or wear indicators. Small robots for inspecting pipelines, sewer systems, and perhaps even railroad tracks certainly would be a welcome addition to a human survey team. These robots probably don’t need to look human, at a small scale, but might look more like a rat or spider. On second thought, maybe they should just look like a robot.

By incorporating artificial intelligence into the mix, the robots of fiction might not be fictional for much longer. Imagine checking into a hospital and interacting with more robots than doctors or nurses — it might not be long before children are being delivered by something that looks less like a Dalek from “Doctor Who” and more like an android from ”I, Robot.” Probably a good thing.