A team at CalTech has developed a flexible rubber layer embedded with sensors and biofuel cells powered by human sweat. It can deliver round the clock data on heart rate, temperature, blood sugar levels and detect metabolic waste products which could be used in the diagnosis of disease.
The team leader, Wei Gao, Assistant Professor in the Andrew and Peggy Cherng Department of Medical Engineering, claims that the e-skin could even provide information on nerve signals controlling our muscles. Previous incarnations of medical monitoring devices have been hampered by the continuous energy requirements needed to run such a system. Until now, they have relied on bulky batteries, which limit the size of the wearable patches.
This latest iteration uses sustainable biofuel cells which break down the lactate present in human sweat, generating electricity and producing water and another harmless by-product of metabolism, pyruvate. The biocells are made from carbon nanotubes infused with a mesh containing a platinum-cobalt catalyst plus an enzyme to break down the lactate.
These slimline cells are capable of generating a continuous and stable supply of electricity of as much as several milliwatts per cm2 for multiple days. The team hope to go on refining their e-skin and fuel cells to enhance and optimise the experience for prosthetic wearers in the future.
This is an exciting development for many reasons. Not only can this new power source improve the lives and motor control of the next generation of prosthetic users, but the treatments for hormonal and endocrine diseases could be controlled and delivered automatically via implants, rendering daily blood tests and insulin injections a thing of the past.
In time, the number and variety of sensors embedded in the e-skin could be extended to track other biomarkers too. If these new e-skin and sweat biofuel cells combine with silk-derived technology developed at Tsinghua University in Beijing, information on markers such as ascorbic acid, uric acid and the electrolytes, sodium and potassium ions could be recorded to an accurate degree. It’s not enough that these biomarkers are detected, the fine fluctuations in concentrations are required for useful health monitoring.
The future of wearable technology is exciting. The new biofuel energy cells allow for the range of trackable markers to expand exponentially. Not only could we wake up to a full report of our sleep efficiency, brain metabolites, and liver and kidney function, we could also monitor the toxins and pollution levels our bodies are exposed to throughout the day.
Our smartphones and apps could then provide tailored advice on reducing negative or harmful effects of those biomarkers and pollutants to achieve a holistic health plan, all powered by our own excretory products.
Those reports could also be sent securely to our medical practitioners, allowing faster diagnosis and accurate treatments. A healthcare revolution is just a few years away. Let us hope that the technology is not limited by price, availability, or privacy legislation, or it is likely to widen the divide in life expectancy between those who can and those who can’t afford this life saving pre-emptive healthcare.
With all that is happening in our world right now, we must keep faith that our scientists will lead us into a future of inexpensive, efficient, and tailored medical treatments based on prevention as much as cure.
Stay safe everyone.