A team of international scientists are working on a way to use people's cells to power different types of biomedical implants.
The team has created a biofuel cell made from carbon nanotubes that generate from blood glucose as a replacement for batteries, according to Discovery News. The researchers said the use of nanotechnology helps improve the biofuel cells' power output and longevity.
Batteries and conventional fuel cells store energy differently, as batteries store chemical energy and fuel cells turn hydrogen, methanol and other forms of fuel into electricity. Scientists have been working on biofuel cells since the 1960s. These cells work similar to the way conventional fuel cells do, except biological enzymes are used to convert glucose into electricity inside the body.
Gordon Wallace, co-author of the University of Wollongong study, said biofuels have run into several challenges, which include "immobilizing" the enzyme and making it stick to the electrodes of the fuel cell so it doesn't diffuse through the cell and into the fuel, as well as making sure the immobilized enzyme stays active for long periods of time, ABC Science reported.
"This is because the electrodes, like anything implanted in the body, tend to get fouled and performance drops off quite quickly with time," Wallace said.
This has has led to the biofuel cell having low power densities (only a few milliwatts per centimeter squared) and a short lifetime of just a few days, Discovery News reported.
The team used carbon nanotubes, microscopic cylinders made from long strings of interconnected carbon atoms, to solve these issues.
The team managed to create a biofuel cell that had an extended lifetime and a higher power density of 2.2 milliwatts per square centimeter. Wallace said that while the difference in power density is not gigantic, it is still impressive.
"What is more significant is the length of time we can operate these biofuel cells for," he said.
The team is looking to use the carbon nanotube yarn biofuel cells to provide power to implants designed for helping regenerate nerve damage, ABC Science reported. In addition, the team aims to make more improvements to the biofuel cells' power output and lifetime, with an ultimate goal of increasing them so the biofuel cells could eventually power a large variety of biomedical implants.
"If you can think of any type of device that is implantable that requires energy, this would be a great way to power it so you don't have to go in and change the batteries all the time," Wallace said.
The research was published in the journal Nature Communications.
