Columbia University says it has developed a self-contained soft actuator that is three times stronger than natural muscle, without the need of external equipment. The research group in the Creative Machines lab led by Hod Lipson, professor of mechanical engineering, says its actuator is a 3D-printable synthetic soft muscle, a “one-of-a-kind artificial active tissue” with intrinsic expansion ability that does not require an external compressor or high voltage equipment as previous muscles required. The new material has a strain density (expansion per gram) that is 15 times larger than natural muscle, and can lift 1000 times its own weight. Previously, no material has been capable of functioning as a soft muscle due to an inability to exhibit the desired properties of high actuation stress and high strain. Existing soft actuator technologies are typically based on pneumatic or hydraulic inflation of elastomer skins that expand when air or liquid is supplied to them. The external compressors and pressure-regulating equipment required for such technologies prevent miniaturization and the creation of robots that can move and work independently. Professor Lipson says: “We’ve been making great strides toward making robots minds, but robot bodies are still primitive. “This is a big piece of the puzzle and, like biology, the new actuator can be shaped and reshaped a thousand ways. Unlike rigid robots, soft robots can replicate natural motion such as grasping and manipulation to provide medical and other types of assistance, perform delicate tasks, or pick up soft objects.