Most of the incredible scientific discoveries are made by accident, especially these that sound crazy and slightly hard-to-believe. The latest invention of this kind is a bio-battery powered by human sweat.
The team behind it is a group of scientist from University of California, San Diego, led by Dr Wenzhao Jia. Although the concept of using human movement to generate energy is not new, the technology is the first one of its kind, which uses lactate, a chemical that is found in sweat after intensive exercise.
Initially, the team had an aim to develop a sleek gadget that can be worn unnoticed by athletes and measure their performance by estimating levels of lactate. While developing the technology in the form of a thin tattoo-type sticker, the scientists discovered that lactate generates electrons and a weak electrical current, which can be harvested. So, they decided to explore further.
The idea is still a proof of concept, and in order to make it viable, the team has to find a way to optimize the enzyme that strips the electrons from lactate. They already established that a person, who is not particularly fit, is more likely to produce much higher levels of lactate, than a trained athlete, which will ultimately result in generation of stronger electrical currents. During the preliminary tests with volunteers, who climbed on exercise bikes, the device was able to produce 70 microwatts per square cm.
The problem that remains is that the scientist would ideally like to maintain the size of the electrodes, which are only a few millimetres thick. They have estimated that they would need to at least double the amount of energy if they are to use it to power a gadget of the size of a watch.
Possible solutions that Dr. Jia and team are exploring right now include an attempt to boost the sensitivity of the device to lactate, as well as an integration of biofuel cells.
It is quite a long shot, although it would be nice if such device ever get realized. Maybe the guys could combine it with the technology that extracts sweat and converts it into drinking water– it could come quite handy to those running in the park every morning.
The methodology is published in the latest issue of the journal Angewandte Chemie.
Image (c) ACS