We have written quite a bit about different sources of energy being invented by various scientists. We investigated several energy harvesting applications like fabrics that can generate electricity from physical movement, a yarn capable of harvesting energy from the motion of ocean waves or from temperature fluctuations and now we are writing about scientists who have developed a small metallic tab that when attached to the body, it can generate electricity from simple movements for tomorrow’s wearable technology.
A New Source of Energy Harvesting for Wearables?
A collaborative research project between the University at Buffalo in the US and the Institute of Semiconductors (IoP) at the Chinese Academy of Science (CAS) has developed a small metallic tab that when attached to the body, can generate electricity from simple movements. Called a triboelectric nanogenerator, the 1.5cm long and 1cm wide tab, can, according to the scientists, deliver a maximum voltage of 124 volts, a current of 10 microamps and a power density of 0.22 milliwatts per square centimetre. This, in theory, could mean that when the triboelectric nanogenerator is attached to the body, it can generate electricity from simple movements – including bending a finger.
Although still early days, the triboelectric nanogenerator was able to power 48 LED lights simultaneously. “No one likes being tethered to a power outlet or lugging around a portable charger,” said lead author Qiaoqiang Gan in a study published by the Nano Energy journal. Dr Gan, from the University of Buffalo’s School of Engineering and Applied Sciences, adds, “The human body is an abundant source of energy. We thought: ‘Why not harness it to produce our own power?'”
After investigating a number of potential nanogenerators capable of producing the triboelectric effect, the breakthrough came when they used two thin layers of gold, with polydimethylsiloxane (also called PDMS, a silicon-based polymer used in contact lenses, Silly Putty and other products) sandwiched in between. “This causes electrons to flow back and forth between the gold layers. The more friction, the greater the amount of power is produced,” said another lead author, Professor Yun Xu of CAS.
According to the Evening Express, the team is now in the next stage of their energy harvesting research, and they are now looking at improving the tab’s performance, which includes using larger pieces of gold. They are also working on developing a portable battery to store energy produced by the tab.