Artificial muscle 'remembers' movements

Artificial muscles that can learn and recall specific movements have been developed by engineers from the University of Cambridge.

The muscles are made from plastic and change size or shape when they receive an electrical signal. Movement can be stored, read, and restored independently. According to the researchers, this is the first time motion control and memory have been combined in a synthetic material. The breakthrough is expected to benefit industries such as robotics, aerospace, exoskeletons and biomedical applications. "Muscles in animals have the ability to both control motion and develop muscle memory in the same tissue, but reproducing these multiple functions in an artificial muscle has not been possible until now," said Dr Stoyan Smoukov, who led the research. After chemically modifying thin strips of a bendable, commercially-available material used in batteries and fuel cells, the researchers programmed a variety of shapes at different temperatures and taught the artificial muscle to 'remember' the movement associated with each shape. The movements were later recovered one-by-one, on demand, by going back to the temperature which was used to programme it. According to the researchers, the restored states can be cycled thousands of times using low voltage inputs (between 1 and 2V). It is these low voltages, together with the potential biocompatibility of the muscles, which the researchers say could lead to bio-implantable devices. Based on the success of the proof of concept material they developed, team is now developing a general methodology to create muscles which incorporate different types of functionality.