Carbon nanotube generator could draw electricity from human bloodstream
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Researchers from Fudan University in Shanghai have developed a carbon nanotube-based power generator which could draw electricity from the flow of blood in veins and arteries.
For millennia, humans have harnessed the natural flow of water – down slopes or in tides – to power mechanical and electrical engines. Water is one of the few renewable sources of energy which is not dependent on the weather, making it an attractive option for governments seeking to reduce their carbon footprint in accordance with the 2015 Paris Agreement.
Now, a team of researchers, led by Professor Huisheng Peng at Fudan University, have created a miniaturised hydroelectric power generator. The device is less than a millimetre in thickness and generates electricity when surrounded by flowing liquid.
To construct the fibre, the researchers wrapped an array of carbon nanotube fibres – spun into highly stable and electrically responsive sheets of less than half a micron in thickness – around a polymer core.
The thread-like “fibre-shaped fluidic nanogenerator” (FFNG) was connected to electrodes and immersed into flowing water, or dipped repeatedly into a saline solution.
An electrical double layer created around the fibre is disturbed by the flowing liquid. This distorts the symmetry of the charge distribution around the fibre, generating a voltage along its length.
“The electricity was derived from the relative movement between the FFNG and the solution,” the researchers said. Encouraged by their finding that the device has high power-conversion efficiency (more than 20 per cent higher than other miniature energy-harvesting devices), the researchers hope to develop helpful applications for the FFNG in the future.
The device can be made stretchable by spinning the carbon nanotube sheets around an elastic substrate and can be woven into fabrics with potential applications in wearable electronics.
The FFNG could prove most useful, however, if it could be placed inside human blood vessels to harvest electrical energy from the bloodstream. Pacemakers, glucose meters and other implanted devices require small amounts of electricity to function, meaning that regular surgeries are required to install new batteries. Replacing the batteries with a nanoscale power generator would remove the need for these invasive and expensive surgeries.
So far, tests of the FFNG to generate electricity from blood flow in frog models have shown promising results.
In 2011, it was reported that engineers from the Bern University of Applied Sciences had placed a miniature turbine inside a blood vessel to generate microwatts of electricity, an alternative means of generating electricity from the human bloodstream.