researchers at graphene flagship at trinity college (dublin, ireland) and the national graphene institute (ngi) at the university of manchester made a surprising breakthrough when graphene was added to polysilicone polymer (otherwise known as silly putty) and demonstrated electrical conductivity.

when graphene was added to silly putty, the polymer demonstrated electrical conductivity.
(graphene flagship)

the conductive polymer was then used to create sensitive electromechanical sensors, according to a report from graphene flagship, which were able to measure breathing, pulse and blood pressure when put on the chest of a human subject. the g-putty, as the researcher referred to the polymer, was “hundreds of times more sensitive than current sensors.”

it was also used as an impact sensor and was able to detect even the footsteps of a small spider.

silly putty was an interesting material for the researchers because of it can flow like a viscous liquid but also bounce like an elastic solid. the electrical resistance of the polymer was very sensitive to deformation and the resistance increased “sharply” when there was slight strain or impact.

“the graphene sheets are able to respond to polymeric deformation in a time dependent manor, forming networks that break and reform during mechanical deformation,” the article stated. “this changes the conductivity of the polymeric material, enabling it to sense by deformation.”

the researchers are confident that this breakthrough will have significant applications in the healthcare field as the material has already proven capable of being used in bio9medical sensors.

the research was recently published in science. the abstract of the report stated:

“despite its widespread use in nanocomposites, the effect of embedding graphene in highly viscoelastic polymer matrices is not well understood. we added graphene to a lightly cross-linked polysilicone, often encountered as silly putty, changing its electromechanical properties substantially.

“the resulting nanocomposites display unusual electromechanical behavior, such as postdeformation temporal relaxation of electrical resistance and nonmonotonic changes in resistivity with strain. these phenomena are associated with the mobility of the nanosheets in the low-viscosity polymer matrix. by considering both the connectivity and mobility of the nanosheets, we developed a quantitative model that completely describes the electromechanical properties.

“these nanocomposites are sensitive electromechanical sensors with gauge factors >500 that can measure pulse, blood pressure, and even the impact associated with the footsteps of a small spider.”