According to a report from IHS last year, the market for wearable technology could grow to as large as $60 billion by 2018. If a team of chemists from UC San Diego has their way, some of those devices could be powered by an unusual source – your sweat.
At the American Chemical Society meeting in San Francisco, Dr. Wenzhao Jia presented a prototype device which uses the lactate in sweat to generate electricity. Using a lactate sensor embedded with an enzyme that liberates electrons from lactate molecules, the device can generate current which could ultimately be used to power low-energy wearable devices.
The sensor is printed onto to temporary tattoo paper and applied to the skin. In tests in which subjects were placed on an exercise bike, they were able to generate up to 70 microwatts per square centimeter of skin. Currently the electrodes in the devices themselves are only 2×3 mm so there is still further development needed in order to generate more energy as well as to store energy produced for later use.
With the growing interest in wearable devices and the ever decreasing amount of energy they require to capture and transmit data, bio-batteries have attracted growing interest as ways to power these batteries without batteries that add bulk and cost. For example, we recently talked about a system from Proteus that uses a wearable patch to capture signals from an ingestible sensor indicating a medication was taken.
And as it turns out, it was the less fit test subjects that generated the most energy. That feature is sure to open up some interesting opportunities if these devices prove to be viable in the coming years.