Powering up wearable technology using flexible generators

By Ashini K Ekanayake

Wearable tech has been all the rage these past few years, with the introduction of the Fitbit and with Apple jumping on the bandwagon with the Apple Watch. These devices all share a common theme, which is to monitor activity and fitness. To take these technologies to the next level, companies have tried to implement features such as the ability to charge devices. However, this was not possible due to the lack of flexibility in generators, making it less comfortable and convenient for the wearer.

However, this is all about to change, due to an innovation by a team at Rice university. Their innovation is a flexible nanogenerator which utilizes the triboeletric effect, where a charge is created when two materials are rubbed together and are subsequently pulled apart. In addition,  the nano generator is metal-free, since it is made out of laser-induced graphene (LIG) which is highly conductive. At this present moment, the device produces a small enough charge to ensure that smaller wearables continue to function. 

Triboelectric nanogenerator on slipper

Triboelectric nanogenerator on slipper

Their experiment, as shown above in the picture, was completed on a slipper, which allowed the wearer of the footwear to generate energy with every step they take, where the graphene’s contact with skin produced a charge in order to power a small capacitor. The lead author of the paper, Michael Stanford stated that “After a 1-kilometer walk, the nanogenerator was able to store 0.22 millijoules of electricity.” This rate of energy conversion has the ability to power wearable sensors and electronics. 

This technology will only grow in prowess in the years to come, and will have numerous other applications. Future developments anticipated include applying these nanogenerators to clothing, rather than just smaller wearables such as smartwatches. Hence, the conversion of energy generated by the body’s movements will allow you to charge your devices, giving a new meaning to the term “power dressing”.