Analysis: The same ingredients found in your kitchen could hold the key to a cleaner, safer future for wearable technology
If someone told you that your next smartwatch could be replaced by a skin patch made from seaweed, starch or even gelatine, you might imagine a sci-fi dinner rather than a medical device. But emerging research is showing that the same ingredients found in your kitchen could hold the key to a cleaner, safer future for wearable technology.
In the future, wearable devices like smartwatches and fitness trackers are foreseen to be replaced by electronic skin patches to transform how we monitor our health. They can track heart rate, temperature, movement and more, all from a flexible device that bends with your body. To make these gadgets soft and stretchable, scientists turned to plastic polymers such as silicone and acrylics, which are cheap, durable and easy to mould.
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The problem is that plastics shed microplastics when they flex, rub against skin or degrade in sunlight. Each time a soft plastic patch is stretched or compressed, tiny bits can break off. Over time, those fragments can enter the environment, or even our bodies, through skin contact, inhalation or ingestion.
When food becomes technology
I wanted to explore whether we could design wearable devices that don’t rely on conventional plastics. The solution is surprisingly familiar: food-based materials. Many everyday foods contain natural polymers, long chains of molecules that give them their structure. Think of the stretch in pizza dough, the wobble of jelly, or the slick surface of seaweed.
These natural polymers can also form flexible, conductive gels that behave much like the plastics used in electronics, without the environmental baggage. That’s how the idea of 'edible electronics' was born. By using ingredients we already trust to eat, we can create wearable materials that are safe for both humans and the planet.
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Seaweed sensors and starch skins
One star ingredient is sodium alginate, extracted from brown seaweed. When mixed with calcium salts (the same kind found in mineral water), it forms soft, jelly-like gels known as hydrogels. In my lab, we’ve used alginate to make flexible films that conduct electricity when blended with nanoscale materials such as graphene, essentially turning seaweed into a smart sensor. Another promising material is starch, the carbohydrate that makes up potatoes, rice and pasta. Starch can be processed into thin, breathable films that flex with the body and naturally break down in soil or water.
Good enough to eat—but not quite yet
So could you literally eat your smartwatch? Not yet, and that's not really the goal. "Edible" in this context means biologically safe and environmentally degradable, not necessarily dinner-ready. But by designing with food-grade materials, we dramatically reduce the risk of harmful microplastic release. If fragments of a starch or seaweed device were ever to shed, they’d break down naturally into sugars or salts rather than persisting as pollutants. In other words, nature already knows how to recycle these materials. We’re simply borrowing that wisdom for modern technology.
Devices made from starch gels can record joint movement, muscle activity or even heartbeats, and then biodegrade harmlessly after use. Even gelatine, the same protein that makes jelly sweets and gummy bears, has surprising potential. When turned into an ultra-thin film, it can host circuits that read heart signals or measure skin hydration. Because gelatine is water-soluble and biocompatible, the device can safely dissolve at the end of its life instead of lingering as waste.
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Balancing performance and sustainability
Critics sometimes assume that green alternatives must perform worse. My findings show that isn’t the case. Seaweed- and starch-based sensors can reach the same sensitivity and flexibility as their plastic counterparts. In some cases, they outperform them because they’re better at letting skin breathe and at handling moisture. The challenge now is to ensure that these materials are stable enough for long-term use while still biodegradable at the end of life.
The bigger picture: healing people and the planet
The global wearable-tech market is expected to exceed €150 billion within a few years. If we continue to rely on petroleum-based plastics, that growth could come with a steep environmental cost. But if even a fraction of future devices were made from natural polymers, the reduction in plastic waste would be enormous. This isn’t just about gadgets; it’s about how we think of materials in medicine. For decades, healthcare innovation has focused on what devices can measure. Now we must also ask what they’re made of.
A taste of what’s to come
Imagine a bandage-like patch made from seaweed that monitors your recovery after surgery and then safely dissolves once you’re healed. Picture biodegradable skin sensors made from starch or protein that could replace single-use medical plastics in hospitals. These aren’t distant dreams; the science already exists. What we need next are collaborations between researchers, manufacturers and policymakers to bring these edible materials from the lab bench to the wristband. By doing so, Ireland could play a leading role in building a truly circular bio-electronics industry, one where the materials feeding our bodies can also feed our technologies.
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The views expressed here are those of the author and do not represent or reflect the views of RTÉ
