Flexible supercapacitor for wearable devices

Flexible supercapacitor for wearable devices

Technology News |
By Nick Flaherty

A team of engineers from the University of Glasgow used layers of graphene and polyurethane to create a flexible supercapacitor combined with a photovoltaic cell. This was used to power a string of 84 LEDs and the high-torque motors in a prosthetic hand, allowing it to grasp a series of objects.

The top touch-sensitive graphene layer developed by the team at the Bendable Electronics and Sensing Technologies (BEST) research group allows sunlight to pass though to a layer of flexible photovoltaic cells below. Any surplus power is stored in a newly-developed supercapacitor, made from a graphite-polyurethane composite. 

The ‘Graphene-Graphite Polyurethane Composites based High-Energy Density Flexible Supercapacitors’, is published in Advanced Science and follows development of a similar supercapcitor ast year using a silver layer. 

The team worked to develop a ratio of graphite to polyurethane which provides a relatively large, electroactive surface area where power-generating chemical reactions can take place, creating flexible supercapacitor that can be charged and discharged quickly and delivers 2.5V, making it more suited for many common applications than other 1V devices.

In laboratory tests, the supercapacitor has been powered, discharged and powered again 15,000 times with no significant loss in its ability to store the power it generates. 

“This is the latest development in a string of successes we’ve had in creating flexible, graphene based devices which are capable of powering themselves from sunlight,” said Professor Ravinder Dahiya (above), Professor of Electronics and Nanoengineering at the University of Glasgow’s School of Engineering, who led the research. “Our previous generation of flexible e-skin needed around 20 nanowatts per square centimetre for its operation, which is so low that we were getting surplus energy even with the lowest-quality photovoltaic cells on the market. We were keen to see what we could do to capture that extra energy and store it for use at a later time, but we weren’t satisfied with current types of energy storages devices such as batteries to do the job, as they are often heavy, non-flexible, prone to getting hot, and slow to charge.”

So the team developed their own supercapacitor. “Our new flexible supercapacitor, which is made from inexpensive materials, takes us some distance towards our ultimate goal of creating entirely self-sufficient flexible, solar-powered devices which can store the power they generate,” said Prof Dahiya. “There’s huge potential for devices such as prosthetics, wearable health monitors, and electric vehicles which incorporate this technology, and we’re keen to continue refining and improving the breakthroughs we’ve made already in this field.”

Related stories:

If you enjoyed this article, you will like the following ones: don't miss them by subscribing to :    eeNews on Google News


Linked Articles