. 24/7 Space News .
CHIP TECH
Stretchable supercapacitors to power tomorrow's wearable devices
by Staff Writers
Durham NC (SPX) Apr 06, 2020

When carbon nanotube forests are placed on an elastomer substrate pre-stretched in two directions, it creates a maze of spaghetti instead of rows, improving the stretchable supercapacitor's performance.

Researchers at Duke University and Michigan State University have engineered a novel type of supercapacitor that remains fully functional even when stretched to eight times its original size. It does not exhibit any wear and tear from being stretched repeatedly and loses only a few percentage points of energy performance after 10,000 cycles of charging and discharging.

The researchers envision the supercapacitor being part of a power-independent, stretchable, flexible electronic system for applications such as wearable electronics or biomedical devices.

The results appear online March 19 in Matter, a journal from Cell Press. The research team includes senior author Changyong Cao, assistant professor of packaging, mechanical engineering and electrical and computer engineering at Michigan State University (MSU), and senior author Jeff Glass, professor of electrical and computer engineering at Duke. Their co-authors are doctoral students Yihao Zhou and Qiwei Han and research scientist Charles Parker from Duke, as well as PhD student Yunteng Cao from the Massachusetts Institutes of Technology.

"Our goal is to develop innovative devices that can survive mechanical deformations like stretching, twisting or bending without losing performance," said Cao, director of the Laboratory for Soft Machines and Electronics at MSU. "But if the power source of a stretchable electronic device isn't stretchable, then the entire device system will be constrained to be non-stretchable."

A supercapacitor (also sometimes referred to as an ultracapacitor) stores energy like a battery, but with some important differences. Unlike batteries, which store energy chemically and generate charges through chemical reactions, an electrostatic double-layer supercapacitor (EDLSC), stores energy through charge separation and cannot create its own electricity. It must be charged from an outside source. During charging, electrons are built up on one part of the device and removed from the other, so that when the two sides are connected, electricity quickly flows between them.

Also unlike batteries, supercapacitors are able to discharge their energy in short but massive bursts, rather than through a long, slow trickle. They can also charge and discharge much faster than a battery and tolerate many more charge-discharge cycles than a rechargeable battery. This makes them perfect for short, high-power applications such as setting off the flash in a camera or the amplifiers in a stereo.

But most supercapacitors are just as hard and brittle as any other component on a circuit board. That's why Cao and Glass have spent years working on a stretchable version.

In their new paper, the researchers demonstrate the culmination of their work to this point, fabricating a stamp-sized supercapacitor that can carry more than two volts. When connecting four together, as many devices require for AA or AAA batteries, the supercapacitors could power a two-volt Casio watch for an hour and a half.

To make the stretchable supercapacitors, Glass and his research team first grow a carbon nanotube forest - a patch of millions of nanotubes just 15 nanometers in diameter and 20-30 micrometers tall - on top of a silicon wafer. That's about the width of the smallest bacteria and height of the animal cell it infects.

The researchers then coat a thin layer of gold nanofilm on top of the carbon nanotube forest. The gold layer acts as a sort of electric collector, dropping the resistance of the device an order of magnitude below previous versions, which allows the device to charge and discharge much faster.

Glass then hands off the engineering process to Cao, who transfers the carbon nanotube forest to a pre-stretched elastomer substrate with the base gold-side-down. The gel-filled electrode is then relaxed to allow the pre-strain to release, causing it to shrink to a quarter of its original size. This process crumples up the thin layer of gold and smashes together the "trees" in the carbon nanotube forest.

"The crumpling greatly increases the amount of surface area available in a small amount of space, which increases the amount of charge it can hold," explained Glass. "If we had all the room in the world to work with, a flat surface would work fine. But if we want a supercapacitor that can be used in real devices, we need to make it as small as possible."

The super dense forest is then filled with a gel electrolyte that can trap electrons on the surface of the nanotubes. When two of these final electrodes are sandwiched close together, an applied voltage loads one side with electrons while the other is drained, creating a charged super-stretchable supercapacitor.

"We still have some work to do for building a complete stretchable electronics system," Cao said. "The supercapacitor demonstrated in this paper doesn't go as far as we want it to yet. But with this foundation of a robust stretchable supercapacitor, we will be able to integrate it into a system that consists of stretchable wires, sensors and detectors to create entirely stretchable devices."

Stretchable supercapacitors, the researchers explain, could power some futuristic devices on their own, or they could be combined with other components to overcome engineering challenges. For example, supercapacitors can be charged in a matter of seconds and then slowly recharge a battery that acts as the primary source of energy for a device. This approach has been used for regenerative breaking in hybrid cars, where energy is generated faster than it can be stored. Supercapacitors increase the efficiency of the whole system. Or as Japan has already demonstrated, supercapacitors can power a bus for urban commuting, completing a full recharging at each stop in the short time it takes to load and unload passengers.

"A lot of people want to couple supercapacitors and batteries together," Glass said. "A supercapacitor can charge rapidly and survive thousands or even millions of charging cycles, while batteries can store more charge so they can last a long time. Putting them together gives you the best of both worlds. They fill two different functions within the same electrical system."

Research Report: "Robust and High-Performance Electrodes via Crumpled Au-CNT Forests for Stretchable Supercapacitors"


Related Links
Duke University
Computer Chip Architecture, Technology and Manufacture
Nano Technology News From SpaceMart.com


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


CHIP TECH
To tune up your quantum computer, better call an AI mechanic
Washington DC (SPX) Apr 01, 2020
A high-end race car engine needs all its components tuned and working together precisely to deliver top-quality performance. The same can be said about the processor inside a quantum computer, whose delicate bits must be adjusted in just the right way before it can perform a calculation. Who's the right mechanic for this quantum tuneup job? According to a team that includes scientists at the National Institute of Standards and Technology (NIST), it's an artificial intelligence, that's who. The tea ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

CHIP TECH
Insects, seaweed and lab-grown meat could be the foods of the future

Construction of Russian National Space Center to be finished in Moscow in 2023

An astronaut's tips for living in space or anywhere

Boeing's first manned Starliner to be launched to ISS on 31 August

CHIP TECH
AEHF-6 launch marks 500th flight of Aerojet Rocketdyne's Rl10 engine

US Space Force launches first mission despite coronavirus

Pentagon tests hypersonic glide body in Hawaii

NASA, SpaceX plan return to human spaceflight from U.S. soil in mid-May

CHIP TECH
NASA's Curiosity Mars rover takes a new selfie before record climb

NASA's Mars Perseverance Rover Gets Its Sample Handling System

Waves in thin Martian air with wide effects

ExoMars to take off for the Red Planet in 2022

CHIP TECH
China's experimental manned spaceship undergoes tests

China's Long March-7A carrier rocket fails in maiden flight

China's Yuanwang-5 sails to Pacific Ocean for space monitoring mission

Construction of China's space station begins with start of LM-5B launch campaign

CHIP TECH
ESA scales down science mission operations amid pandemic

Venezuelan communications satellite out of service

RUAG Space delivered key products for Airbus OneWeb satellite launch

OneWeb launches 34 communications satellites from Kazakhstan

CHIP TECH
Technique reveals how crystals form on surfaces

Zoom under scrutiny in US over privacy, porn hacks

World Centric announces new World Centric leaf fiber lids

Creating custom light using 2D materials

CHIP TECH
Salmon parasite is world's first non-oxygen breathing animal

Warped Space-time to Help WFIRST Find Exoplanets

Paired with super telescopes, model Earths guide hunt for life

Planetary Science Journal launches with online papers

CHIP TECH
Jupiter's Great Red Spot shrinking in size, not thickness

Researchers find new minor planets beyond Neptune

Ultraviolet instrument delivered for ESA's Jupiter mission

One Step Closer to the Edge of the Solar System









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.