A small patch created and designed by the National University of Singapore is seen as a new-age device harvests electricity from muscle movements. The energy harvested may then be utilized to power smaller electrical devices such as an iWatch or even Fitbit!
We live in a day and age where anything is technologically possible, and we think it’s one of the most daring and exciting ages to exist in!
The researchers created this small device by allowing it to harvest static electricity (static electricity is what makes your hair stand up like Medusa when rubbing a balloon on it) and then convert it into electrical energy. This scientific phenomenon is called the triboelectric effect, which produces electrical energy when pressure is put on it (unlike piezoelectric materials). To allow for this effect to take place, two varying surfaces must be put into close contact in order to produce the static that is required.
When the materials are then pulled apart, a difference is created whereby allowing for a current to flow between the two materials. This is then collected utilising the aid of an electrode.
The device created by the triboelectric effect is so powerful, that a size as small as a stamp is able to produce 7.5 V of electric potential just by having you flex your fist. If it is tapped, it may generate close to 90 V of open circuit voltage and 0.8 mW, which is enough electricity needed to light 12 traditional LEDs, reported Prachi Patel reports for IEEE Spectrum.
Demonstration of the patch took place at the IEEE International Conference on Micro Electro Mechanical Systems (MEMS) 2015 in Portugal during January, by engineering professor Chengkuo Lee.
The patch may utilized as a wearable and self-powered sensor that may keep track of your activity and movements during the day.
If such technology is scaled upon, new types of wearable electronic devices may be developed that will not need battery power, as the wearer chargers it by keeping busy, such as walking or even holding objects. Charging will take place for as long as the wearer is not staying still, as such you will never have to worry about battery power running out again.
Lee and the team developed this unique material by using thousands of small pillar-like structures which are then stuck into a flexible silicon layer. The pillar structures allow for greater surface area on the material itself, which allows for more friction to take place.
The patch of material has 50 nm-thick layer of gold backing, which aids as an electrode in harvesting the static electricity. Therefore it’s say to say that the device doesn’t draw electricity from the wearer’s body, but rather just uses the friction created to power itself.
The wearer’s skin helps in creating the friction needed, as LokeshDhakar, Lee’s graduate student, told IEEE Spectrum.“Skin, the most abundant surface on a human body, is a natural choice for one of the triboelectric layers.”
“Also skin as a triboelectric material has a high tendency to donate electrons or get positively charged which is important in improving the performance of the device if the other triboelectric layer intentionally chosen as the one with a tendency to get negatively charged.”
The team has conducted tests by having subjects wear the patch of their throats or forearm and have concluded that it can produce enough power to run a sensor.
Even though this team is not the first to build such devices (2013 was the year that a USA team created a bigger and better powered triboelectric generator) but the USA led team utilised indium tin oxide acting as an electrode, allowing for much less flexibility.
The aim of the Singapore led team is to be able to charge bigger devices such as mobile phones and even laptops just by using the rubbing motion of the wearer’s skin. Integrating this technology into wearable electronics is the next step before it may be scaled up even further.
Photo Credit : spectrum.ieee.org