AMBER researchers use graphene to make state of the art sensors from silly putty

8 December 2016

Researchers in AMBER, the Science Foundation Ireland-funded materials science research centre, hosted in Trinity College Dublin, have used the wonder material graphene to make the novelty children’s material silly putty® (polysilicone) conduct electricity, creating extremely sensitive sensors. This world first research, led by Professor Jonathan Coleman from TCD and in collaboration with Prof Robert Young of the University of Manchester, potentially offers exciting possibilities for applications in new, inexpensive devices and diagnostics in medicine and other sectors. The AMBER team’s findings have been published this week in the leading journal Science*.

Prof Coleman, Investigator in AMBER and Trinity’s School of Physics along with postdoctoral researcher Conor Boland, 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 even blood pressure. It showed unprecedented sensitivity as a sensor for strain and pressure, hundreds of times more sensitive than normal sensors. The G-putty also works as a very sensitive impact sensor, able to detect the footsteps of small spiders. It is believed that this material will find applications in a range of medical devices.

Prof 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 as 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.”

He continued, “While a common application has been to add graphene to plastics in order to improve the electrical, mechanical, thermal or barrier properties, the resultant composites have generally performed as expected without any great surprises. The behaviour we found with G-putty has not been found in any other composite material. This unique discovery will open up major possibilities in sensor manufacturing worldwide.”

Professor Mick Morris, Director of AMBER, said: “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.”

Prof Coleman is a partner in Graphene flagship, a €1 billion EU initiative to boost new technologies and innovation during the next 10 years.

A video about the new material G-putty is available here, http://ambercentre.ie/site/media.

* Sensitive electromechanical sensors using viscoelastic graphene-polymer nanocomposites, Boland et al, Science 9 Dec 2016 (http://www.sciencemag.org/)

About Graphene

Graphene consists of atomically thin layers of carbon atoms and has a range of superlative properties – the strongest and most conductive material among others.

Prof Coleman was announced as a recipient of a €2.2m European Research Council (ERC) Advanced Grant earlier this year. The prestigious ERC Advanced Grants are only made to Europe’s most distinguished researchers. Coleman’s work has been published in prestigious international journals such as Science, Nature, Nature Nanotechnology, Nature Materials and nature Communications, as well as featuring in New Scientist, the New York Times and on CNN. He was recently included by Thomas Reuters in their Highly Cited Researchers 2016 list.

About AMBER

AMBER (Advanced Materials and BioEngineering Research) is a Science Foundation Ireland funded centre which provides a partnership between leading researchers in materials science and industry to develop new materials and devices for a range of sectors, particularly the ICT, medical devices and industrial technology sectors. The centre is hosted in Trinity College Dublin, working in collaboration with CRANN (Centre for Research on Adaptive Nanostructures and Nanodevices), the Trinity Centre for Bioengineering and with University College Cork and the Royal College of Surgeons of Ireland.

About the Graphene Flagship

The Graphene Flagship is the EU’s biggest ever research initiative. With a budget of €1 billion, it represents a new form of joint, coordinated research initiative on an unprecedented scale. Through a combined academic-industrial consortium, the research effort covers the entire value chain, from materials production to components and system integration, and targets a number of specific goals
that exploit the unique properties of graphene.

Tasked with bringing together academic and industrial researchers to take graphene from the realm of academic laboratories into European society in the space of 10 years, the Graphene Flagship hopes to facilitate economic growth, new jobs and new opportunities for Europeans as both investors and employees.

http://graphene-flagship.eu