To an average person, the human body is a massive multicellular uncertainty. Every second of every day, right under your nose, the trillions of cells comprising your giant meat suit of a body go about the business of keeping you alive, without so much as checking in.
A fundamental part of owning a human body is knowing this: everything is happening, and you can only assume that it’s going to plan. If something is suddenly not going to plan, you will eventually be made aware of it. More often than not, this will be a huge and deeply stressful inconvenience.
But what if we could see disaster coming? What if we could keep track of these seemingly unsupervised bodily processes, and catch malfunction early?
For hundreds of years, the best we could come up with in the way of measurement was pedometers. The earliest emerged in the 15th century, but no one took much notice until the 1960s, when the popularity and accessibility of cars led to a sudden removal of Nature’s simplest keep-fit tactic: walking.
Fast forward to 10,000 step targets and hundreds of years of health developments, and you’ll reach today’s pedometer-filled reality. But there’s more! The recent revolution in wearable technology has allowed for not just step-counting, but sleep-tracking, and even heart rate monitoring, all available at the flick of a wrist.
So, what comes next?
Enter “drawn-on-skin” (DoS) electronics, the brainchild of Professor Cunjiang Yu and his team at the University of Houston, published last month in Nature Communications. These tattoo-like devices stand to revolutionise wearable technology for one simple reason: they won’t budge.
A Fitbit is great, but it’ll move when you move. You take it off to shower, and forget to put it back on, or move in such a way that it doesn’t record the change. This doesn’t matter much when you’re only keeping track of steps, but the resulting imprecision of data like heart rate can have significant impacts if used for diagnostics and health monitoring.
The current alternative is “wearable bioelectronics”, technological patches which can be attached to the skin. These devices produce more accurate information than smartwatches, and are used for monitoring, preventing, and treating illness or injury. However, they can still be disrupted when their sensors don’t move precisely with the skin.
Drawn-on-skin devices, on the other hand, are applied “like you would use a pen to write on a piece of paper”, Yu says. Comprising three “electronic inks”, DoS devices are applied to the body “on-demand in a freeform manner”, to create critical sensors.
These drawn-on sensors can collect data on temperature, muscle signals, and skin hydration, as well as other electrophysiological factors like heart rate. They can be adapted to collect different types of information, and even demonstrate an ability to accelerate wound healing.
Such seamless data collection is expected to be particularly useful in technologically-starved situations like battlegrounds, especially since the “simplicity of the drawing process” means that anyone and everyone can create DoS devices on demand. Yu’s team have even produced stencils for their designs, ensuring that neither artistic or scientific skill is required to apply them.
Pedometers one day, Fitbit the next – and perhaps, Yu’s smaller and smarter devices on the horizon.