Researchers at AMBER, the Science Foundation Ireland-funded materials science centre, and the School of Physics, Trinity College Dublin, have discovered a method of creating wearable sensors by adding graphene to shop-bought rubber bands; the first time this has ever been achieved worldwide. Working with researchers from the University of Surrey, their findings have been published in ACS Nano, a leading international nanoscience publication.
The team - led by Professor of Chemical Physics at Trinity, Jonathan Coleman, one of the world’s leading nanoscientists - infused rubber bands with graphene, a nano-material derived from pencil lead which is 10,000 times smaller than the width of a human hair. This process is simple and compatible with normal manufacturing techniques. While rubber does not normally conduct electricity, the addition of graphene made the rubber bands electrically conductive without degrading the mechanical properties of the rubber. Tests showed that any electrical current flowing through the graphene-infused rubber bands was very strongly affected if the band was stretched. As a result, if the band is attached to clothing, the tiniest movements such as breath and pulse can be sensed.
The discovery opens up a host of possibilities for the development of wearable sensors from rubber, which could be used to monitor blood pressure, joint movement and respiration. Other applications of rubber-graphene sensors could be in the automotive industry (to develop sensitive airbags); in robotics, in medical device development (to monitor bodily motion), as early warning systems for cot death in babies or sleep apnoea in adults. They could also be woven into clothing to monitor athletes’ movement or for patients undergoing physical rehabilitation.
The discovery was welcomed by Minister for Research and Innovation Damien English TD, who said: "This exciting discovery shows that Irish research is at the leading edge of material science worldwide. AMBER is one of a number of research centres funded by the Government to carry out world-class research in collaboration with industry in strategic areas of opportunity for Ireland. Material science underpins a wide range of market opportunities that have the greatest potential to deliver economic return through enterprise development, employment growth and job retention in Ireland. This discovery is a key stepping stone in our strategy of turning good ideas into good jobs. I congratulate Professor Coleman, his team and collaborators at AMBER for this great discovery and wish them well for the future."
Professor Coleman said: “Sensors are becoming extremely important in medicine, wellness and exercise, medical device manufacturing, car manufacturing and robotics, among other areas. Biosensors, which are worn on or implanted into the skin, must be made of durable, flexible and stretchable materials that respond to the motion of the wearer. By implanting graphene into rubber, a flexible natural material, we are able to completely change its properties to make it electrically conductive, to develop a completely new type of sensor. Because rubber is available widely and cheaply, this unique discovery will open up major possibilities in sensor manufacturing worldwide.”
Corresponding author, Dr Alan Dalton from the University of Surrey continued: “Until now, no such sensor has been produced that meets needs and that can be easily made. It sounds like a simple concept, but our graphene-infused rubber bands could really help to revolutionise certain aspects of healthcare.”
Professor Mark Ferguson, Director General of Science Foundation Ireland and Chief Scientific Adviser to the Government of Ireland said: “Congratulations to Professor Coleman and his team on this discovery. Science Foundation Ireland is committed to funding impactful research which will lead to new products and services of the future. Just over a year since it was established as an SFI Research Centre, AMBER’s researchers are working to address the big issues facing modern society – across healthcare, energy, transport and other areas. It is this type of research that has led to Ireland’s international position as 3rd for nanoscience and 6th for materials science. I look forward to future developments from this team.”
The paper, Sensitive, High Strain, High-rate, bodily motion Sensors based on Graphene-Rubber Composites, is available here.