Scientists at the University of Sussex and the University of Brighton have developed health sensors using natural elements like rock salt, water and seaweed, combined with graphene.
Since they are made with ingredients found in nature, the sensors are fully biodegradable, making them more environmentally friendly than commonly used rubber and plastic-based alternatives. Their natural composition also places them within the emerging scientific field of edible electronics – electronic devices that are safe for a person to consume.
The researchers found that their sustainable seaweed-based sensors actually outperform existing synthetic based hydrogels and nanomaterials, used in wearable health monitors, in terms of sensitivity. This also means improvement in accuracy, as the more sensitive a sensor, the more accurately it will record a person’s vital signs.
The idea to use seaweed in a health monitoring device was raised when lead scientist Dr. Conor Boland, a physicist at the University of Sussex, was watching TV during lockdown. Dr. Boland said: “I was first inspired to use seaweed in the lab after watching MasterChef during lockdown. Seaweed, when used to thicken deserts, gives them a soft and bouncy structure – favored by vegans and vegetarians as an alternative to gelatin. It got me thinking: “what if we could do that with sensing technology?”. “For me, one of the most exciting aspects to this development is that we have a sensor that is both fully biodegradable and highly effective. The mass production of unsustainable rubber and plastic based health technology could, ironically, pose a risk to human health through microplastics leeching into water sources as they degrade. As a new parent, I see it as my responsibility to ensure my research enables the realization of a cleaner world for all our children.”
Seaweed is an insulator, but by adding a critical amount of graphene to a seaweed mixture the scientists were able to create an electrically conductive film. When soaked in a salt bath, the film rapidly absorbs water, resulting in a soft, spongy, electrically conductive hydrogel.
The development has the potential to gretly impact health monitoring technology, as future applications of the clinical grade wearable sensors would look something like a second skin or a temporary tattoo: lightweight, easy to apply, and safe, as they are made with all natural ingredients. This would significantly improve the overall patient experience, without the need for more commonly used and potentially invasive hospital instruments, wires and leads.
Dr. Sue Baxter, Director of Innovation and Business Partnerships at the University of Sussex, is excited about the potential benefits of this technology: “At the University of Sussex, we are committed to protecting the future of the planet through sustainability research, expertise and innovation. What’s so exciting about this development from Dr Conor Boland and his team is that it manages to be all at once truly sustainable, affordable, and highly effective – out-performing synthetic alternatives. What’s also remarkable for this stage of research – and I think this speaks to the meticulous ground-work that Dr Boland and his team put in when they created their blueprint – is that it’s more than a proof of principle development. Our Sussex scientists have created a device that has real potential for industry development into a product from which you or I could benefit in the relatively near future.”