Engineering news
Researchers at the University of Sussex have created extremely sensitive, unobtrusive sensors that could track babies' heart and breathing rates, and send automatic updates to doctors or parents.
The technology is based on a new conductive liquid developed by Alan Dalton and his team of physicists at Sussex. They created the liquid from an emulsion of graphene, water and oil, and it's described in a paper in the journal Nanoscale.
When a channel or tube holding this liquid is stretched, even by a small amount, the conductivity of the liquid inside changes. This means it can be used to track respiration rates and pulses – even with tiny signals.
“When the graphene particles are assembled around the liquid droplets, electrons can hop from one particle to the next; this is why the whole liquid is conductive,” explained Matthew Large, lead researcher on the project. “When we stretch our sensors we squeeze and deform the droplets; this moves the graphene particles further apart and makes it much harder for the electrons to hop across the system.”
The researchers say their device is the most sensitive liquid-based device ever reported. The team hope to embed this technology into a fitness tracker-style band, or a sensor vest that a baby could wear, as a replacement for the clunky sensors that are currently attached to the feet or hands of at-risk infants and are connected with restrictive wires.
“Using the conducting liquid emulsions we have developed, we will produce cheap, wearable sensors based on graphene,” said Dalton. “The devices will be comfortable, non-invasive and can provide intuitive diagnostics of breathing and heart rate. We will eventually have a suit that the baby can wear which will read-out all vital information wirelessly. We hope to see this made available within two to four years.”
Dalton said he was inspired to create the liquid while making salad dressing – a type of emulsion – at home with his daughter, and he added that the affordable technology has wide-ranging potential. “Anyone interested in tracking their heart or respiration rates –joggers, for example – may be interested to wear this technology within their exercise gear,” he said.
Michael Sawh, the editor of Wareable, told Professional Engineering that there had been a lot of excitement around graphene in the wearables industry. "It’s both tough and light, flexible and fire resistant. It also has the potential to make components smaller without sacrificing power and this is really key for wearables," he said. "It finally feels like we are edging much closer to seeing graphene cropping up in smartwatches, fitness trackers and other devices that should not only improve how well they perform, but also opens up the door for even greater innovation."