Researchers from Monash University have come a step closer to producing miniature robots that can enter the bloodstream and perform surgeries, with graphene oxide as an effective shape memory material.
Shape memory effects have been, until now, only observed in materials larger than approximately 10nm but graphene oxide is approximately 1nm thick. In contrast to other shape memory materials, the Monash team discovered that subjecting certain forms of graphene oxide to an electric field caused shape changes almost instantaneously and retained the new form until stretched back to its original shape.
The team said the shape memory effect arises from an atomic switch enabling a super-fast response. According to the researchers, aside from being able to transform at high speeds, graphene oxide has many other advantages over existing shape memory materials. It is incredibly light, has a high density to strain ratio, is very stable, and is able to perform a relative size change of 15%, compared to shape memory alloys, which only change by 4%.