* prototypes three times larger than a red blood cell have been made
* they are working on the microscale actuator muscles

Above – Graphene-glass bimorphs can be used to fabricate numerous micron-scale 3-D structures, including (top to bottom) tetrahedron, helices of controllable pitch, high-angle folds and clasps, basic origami motifs with bidirectional folding, and boxes. Credit: Marc Miskin, Cornell University

The machines move using a motor called a bimorph. A bimorph is an assembly of two materials – in this case, graphene and glass – that bends when driven by a stimulus like heat, a chemical reaction or an applied voltage. The shape change happens because, in the case of heat, two materials with different thermal responses expand by different amounts over the same temperature change.