Irish scientists create graphene sensor for wearable medical devices

29 Apr 2021

The graphene-based sensor. Image: AMBER

A team at Trinity College Dublin is currently exploring medical applications for its flexible graphene-based sensor.

Graphene has been hailed as a ‘wonder material’ as it is incredibly strong, but also light and flexible.

Now, scientists in Ireland are making use of these properties with a development that could have applications in the areas of wearable electronics and medical diagnostic devices.

Researchers at Trinity College Dublin’s School of Physics and at AMBER, the Science Foundation Ireland research centre for advanced materials, have developed a next-generation graphene-based sensing technology.

The team is led by nanoscientist Prof Jonathan Coleman, who is head of the School of Physics at Trinity. Coleman’s team has previously created nanocomposites of graphene with polymers including those found in rubber bands and silly putty.

“We have now turned G-putty – our highly malleable graphene-blended silly putty – into an ink blend that has excellent mechanical and electrical properties,” he explained.

The researchers demonstrated that they can produce a low-cost, printed graphene nanocomposite strain sensor. This involved formulating a G-putty-based ink that could be printed as a thin film onto elastic substrates, like a Band-Aid, and attached easily to the skin.

A strain sensor is a diagnostic tool that can be used to measure changes in mechanical strain such as pulse rate or a person’s ability to swallow. It detects this mechanical change and converts it into an electrical signal.

The team said that these new printed graphene sensors are more sensitive than the industry standard and outperform other comparable nano-enabled sensors when it comes to flexibility.

“Our inks have the advantage that they can be turned into a working device using industrial printing methods, from screen printing to aerosol and mechanical deposition,” Coleman added.

Exploring applications

The team is now looking at translating this research, which was published in the journal Small, into a product.

Dr Daniel O’Driscoll from Trinity’s School of Physics said the development of these sensors represents a “considerable step forward” in the area of wearable diagnostic devices that could be incorporated into clothing or mounted to a patient’s skin.

“We’re currently exploring applications to monitor real-time breathing and pulse, joint motion and gait, and early labour in pregnancy,” he added.

“Because our sensors combine high sensitivity, stability and a large sensing range with the ability to print bespoke patterns onto flexible, wearable substrates, we can tailor the sensor to the application. The methods used to produce these devices are low cost and easily scalable – essential criteria for producing a diagnostic device for wide-scale use”.

Earlier this year, Coleman won a €150,000 Proof of Concept grant from the European Research Council to build on the research results and begin to develop a prototype for a commercial product.

The ultimate aim of the group is to identify potential investors and industry partners, and form a spin-out that could focus on both recreational and medical applications of this technology.

Sarah Harford was sub-editor of Silicon Republic