These Soft Robots Use Shape Memory Alloy to Replicate Natural Muscle

Evolution is an extremely powerful force, and over millions of years it has molded animals into incredibly efficient biological systems. A human, for instance, can walk an entire mile using just 100 calories — about one medium sized apple’s worth. That’s in stark contrast to robots today, which move inefficiently in comparison. That’s why Carmel Majidi’s Soft Machines Lab at Carnegie Mellon University is working on new soft robots that attempt to recreate natural muscle.

The goal of this research, which is a collaboration with the University of California, Los Angeles and the University of Nevada, Reno, is to develop artificial actuators for robots that more closely mirror their natural counterparts. The musculature of animals, including insects, is impressive in its efficiency. To replicate the efficiency of a human, a 180lb bipedal robot would need to be able walk that mile using just 32 AA batteries (about 80Ah) — a very challenging proposition.

This research is intended to close that gap, starting with insect-like locomotion. To accomplish that, they’ve constructed two small robots: one with four legs, and another that resembles a caterpillar. Each has legs constructed from shape metal alloy and thermally-conductive elastomer. These leg actuators are far more efficient than traditional motor-driven types, and can also move quickly. The result is a robot that can move with very little power, and that opens the doors to more complex robots that could be dramatically more efficient than current models.