Artificial muscles spring into action with mandrel-free fabrication technique

Researchers from The University of Texas at Dallas; Texas State University in San Marcos, TX; and Lintec of America in Plano, TX, as well as international collaborators,  have invented a new, inexpensive method in which fibers are coiled to make springlike artificial muscles. What’s unique about this method is that it doesn’t make use of a mandrel – a spindle that serves to support or shape the artificial muscles. The mandrel-free fabrication process involves inserting twist into individual fibers, causing them to coil back on themselves, and then plying the twisted fibers to create springlike coils. The researchers used the mandrel-free method to make high-spring-index carbon nanotube yarns, which could be used to harvest mechanical energy or as self-powered strain sensors.