This Skin Patch Acts Like a Battery-Free Fitbit

If you want to stay healthy, you need to be proactive. It’s not enough to go see a doctor when something goes wrong, you should be aware of your physical health at all times. Currently, that means getting regular check-ups and using a device like a Fitbit to track your activity and overall health. But a fitness tracker just monitors a few data points, and only works if you actually use it. That’s why a team of researchers have come up with an advanced, battery-free patch to monitor your health.

The patch is roughly the size of a quarter, and is designed to gather data about your health by analyzing your sweat. It doesn’t require a battery, and instead the patch produces power by harvesting the ambient radio waves that are virtually always zipping through the air around us. That means you can simply place the patch on your skin and forget about it.

Surprisingly, there is quite a lot of data that can be gathered from your sweat. Just the amount of sweat and its pH levels are useful. It can also chemically check for lactate, glucose, hydration, and electrolyte levels — all of which are helpful in quantifying your health. That data can then be transmitted to a smartphone using NFC (Near-Field Communication) technology.

For practicality, the patch has been divided into two parts: the disposable, microfluidic collection section, and the reusable electronics. That means that each disposable patch would be very affordable. Most importantly, users would be more likely to actually wear these patches. Fitbits and other wearable fitness trackers are bulky, uncomfortable, and require recharging, while these patches would be far more convenient and unobtrusive.