TV Cookery Inspires Scientists to Create Edible Electronics Based on a Functionalized Seaweed Gel

A team of researchers at the Universities of Sussex and Brighton has come up with a way to create biodegradable — and even edible — sensors and other electronics using seaweed.

"I was first inspired to use seaweed in the lab after watching MasterChef during lockdown," explains corresponding author Conor Boland, PhD, of the project's origins. "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?'"

The team's work aims to replace synthetic materials with natural ones, building a hydrogel out of rock salt, water, and seaweed, which is functionalized using graphene. The resulting material, which can be applied like a "second skin" for use in wearable electronics, is fully biodegradable — and, unusually, edible, though not exactly designed for flavor.

Traditionally, seaweed would act as an electrical insulator rather than a conductor. Mixed with graphene, though, it forms a conductive film — which, when soaked in a salt-water bath, absorbs moisture to become a soft and malleable hydrogel. The resulting hydrogel also acts as a sensor, with the electrical resistance altering in response to applied strain or pressure — allowing it to be applied to skin as a movement or contact sensor sensitive enough to measure an object equivalent in mass to a single drop of rain.

"For me," Boland concludes, "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."

"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," claims Sue Baxter, PhD, director at the University of Sussex. "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."

The team's work has been published in the journal ACS Sustainable Chemistry & Engineering under open-access terms.