Singapore – A team of scientists at Nanyang Technological University in Singapore have created a soft, stretchable prototype battery that is powered by human perspiration.
The batteries are 3D printed onto a very absorbent stretchable textile, using a hydrophilic poly(urethane-acrylate) containing silver flakes. When the flakes come into contact with sweat, its acidity and chloride ions cause them to clump together, causing an electric current to flow between the electrodes.
NTU scientists Gurunathan Thangavel, Lee Pooi See and Lyu Jian, who carried out the research
The 2cm square batteries can be affixed to wearable devices such as watches or wristbands. They are much thinner than the traditional button batteries that wearable sensors rely upon.
Their ability to generate electricity was tested in the lab using artificial human sweat. A human trial was also carried out, with a person wearing the battery on their wrist while cycling on a stationary bicycle for 30mins. They generated a voltage of 4.2V and output power of 3.9mW. This was enough to power a commercial temperature sensor, and send its data continuously via Bluetooth to a smartphone.
‘Our technology heralds a previously unreachable milestone in the design of wearable devices,’ said Lee Pooi See, who led the research. ‘By capitalising on a ubiquitous product, perspiration, we could be looking at a more environmentally friendly way of powering wearable devices that does not rely on conventional batteries. It is a near-guaranteed source of energy produced by our bodies. We expect the battery to be capable of powering all sorts of wearable devices.’
The work has been published in the journal Science Advances.
