Harvesting human energy

Ever considered how useful it would be to power your mobile phone just by going for a walk? Well, harvesting human energy could be the next big thing.

Engineering researchers at the University of Wisconsin-Madison have published a paper in the journal Nature Communications that reveals how energy- harvesting technology could make it possible to do just that.

At the moment, energy-harvesting technologies are being utilised by high- power applications, such as solar and wind energy, and by calculators and watches, which are low-power applications. As yet, there has not been a solution that powers mobile electronic devices.

Tom Krupenkin, a professor of mechanical engineering at the university, explains, ‘Humans, generally speaking, are very powerful energy-producing machines. While sprinting, a person can produce as much as a kilowatt of power.’

Here comes the science bit. The technology discovered by Krupenkin and his colleague J Ashley Taylor is called ‘reverse electrowetting’. It converts mechanical energy to electrical energy using a micro-fluidic device consisting of thousands of liquid micro-droplets that interact with a novel nano-structured substrate.

In short, this means that an energy harvester that could be embedded in footwear would capture the energy created by walking and turn it into electrical power.

The researchers envisage a couple of ways in which this power can be harnessed. The energy generated could directly power consumer electronic devices, or it could integrate with a Wi-Fi hot spot, allowing the energy to power a device without being physically connected.

Krupenkin and Taylor are now hoping to commercialise the technology, which means it could be just a few years before you can literally go for a ‘power walk’.