G-putty is a polysilicone polymer infused with graphene. Polysilicone polymer is better known as Silly Putty®, a stretchy, moldable product sold in toy stores. Graphene is a highly-conductive carbon allotrope whose atoms are arranged in a mesh-like shape just one atom thick. The qualities of G-putty make it an ideal material for sensors.
The addition of graphene makes the substance conductive, as expected, but the researchers found that it also made it a high-performance material for sensing pressure, impact and deformation. Even a tiny strain or impact causes the resistance of the substance to increase dramatically; over time, as it regains its original shape, the resistance tends to return to its original level. That happens because the mesh-like structure of the graphene allows it to form and break networks as the substance is deformed.
The researchers who discovered the special qualities of G-putty foresee its use in medical and health-related sensors. When they placed a silly putty sensor on a person’s chest, for example, they found they could monitor his breathing. A sensor placed over the carotid artery could not only measure the person’s pulse rate but could also monitor his blood pressure continuously, which has heretofore been a more difficult task.
G-putty was developed as a collaborative effort of Graphene Flagship at Trinity College Dublin and the National Graphene Institute (NGI) at The University of Manchester, led by Professors Johnathan Coleman and Robert Young, respectively.