© University of the Fraser Valley
© University of the Fraser Valley

Scientists create electronic sensors from Graphene

Researchers in Advanced Materials and BioEngineering Research (AMBER) at the Trinity College Dublin (TCD), Ireland, have used graphene to make novelty children’s silly putty® conduct electricity.

The research was led by Professor Jonathan Coleman from TCD, in collaboration with Professor Robert Young from the University of Manchester, UK.

The researchers discovered that the electrical resistance of putty infused with graphene (G-putty) was extremely sensitive to the slightest deformation or impact. They mounted the G-putty onto the chest and neck of human subjects and used it to measure breathing, pulse and blood pressure. It showed unprecedented sensitivity to strain and pressure. The G-putty also worked as a highly sensitive impact sensor, able to detect the footsteps of small spiders.

Coleman said: “What we are excited about is the unexpected behaviour we found when we added graphene to the polymer, a cross-linked polysilicone. This material is well known as the children’s toy silly putty. It is different from familiar materials in that it flows like a viscous liquid when deformed slowly, but bounces like an elastic solid when thrown against a surface. When we added the graphene to the silly putty, it caused it to conduct electricity, but in a very unusual way.

“The electrical resistance of the G-putty was very sensitive to deformation with the resistance increasing sharply on even the slightest strain or impact. Unusually, the resistance slowly returned close to its original value as the putty self-healed over time.”

Professor Mick Morris, director of AMBER, added: “This exciting discovery shows that Irish research is at the leading edge of materials science worldwide.

“Jonathan Coleman and his team in AMBER continue to carry out world class research and this scientific breakthrough could potentially revolutionise certain aspects of healthcare.”

The AMBER team’s findings have been published in the journal Science.