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The sensors, similar to those worn by runners or medical patients to monitor heart rate and temperature, were developed by researchers at the University of Sussex.
Made solely of natural ingredients, the sensors are fully biodegradable, making them more environmentally friendly than commonly used rubber and plastic-based materials.
Their natural composition also gives them the unusual benefit of being ‘edible electronics’, a research announcement said. The researchers did not say how the sensors taste, however, and eating them after use might not be advisable.
The team also reported that their sustainable seaweed-based sensors outperform the sensitivity of existing synthetic based hydrogels and nanomaterials that are used in wearable health monitors.
The project had an unlikely inspiration, according to lead scientist Dr Conor Boland. “I was first inspired to use seaweed in the lab after watching MasterChef during lockdown,” said Dr Boland. “Seaweed, when used to thicken desserts, gives them a soft and bouncy structure – favoured by vegans and vegetarians as an alternative to gelatine. 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.”
Seaweed is first and foremost 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.
Future applications of the clinical grade wearable sensors could look something like a second skin or a temporary tattoo – lightweight, easy to apply, and safe. This would “significantly improve” the overall patient experience, the researchers claimed.
Dr Sue Baxter, director of innovation and business partnerships at the University of Sussex, said: “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 – outperforming synthetic alternatives.
“What’s also remarkable for this stage of research – and I think this speaks to the meticulous groundwork 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… in the relatively near future.”
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