Clever battery completes stretchable electronics package

The rechargeable battery can stretch, twist and bend -- and return to normal shape

2013-02-26

(Press-News.org) Northwestern University's Yonggang Huang and the University of Illinois' John A. Rogers are the first to demonstrate a stretchable lithium-ion battery -- a flexible device capable of powering their innovative stretchable electronics.

No longer needing to be connected by a cord to an electrical outlet, the stretchable electronic devices now could be used anywhere, including inside the human body. The implantable electronics could monitor anything from brain waves to heart activity, succeeding where flat, rigid batteries would fail.

Huang and Rogers have demonstrated a battery that continues to work -- powering a commercial light-emitting diode (LED) -- even when stretched, folded, twisted and mounted on a human elbow. The battery can work for eight to nine hours before it needs recharging, which can be done wirelessly.

The new battery enables true integration of electronics and power into a small, stretchable package. Details will be published Feb. 26 by the online journal Nature Communications.

"We start with a lot of battery components side by side in a very small space, and we connect them with tightly packed, long wavy lines," said Huang, a corresponding author of the paper. "These wires provide the flexibility. When we stretch the battery, the wavy interconnecting lines unfurl, much like yarn unspooling. And we can stretch the device a great deal and still have a working battery."

Huang led the portion of the research focused on theory, design and modeling. He is the Joseph Cummings Professor of Civil and Environmental Engineering and Mechanical Engineering at Northwestern's McCormick School of Engineering and Applied Science.

The power and voltage of the stretchable battery are similar to a conventional lithium-ion battery of the same size, but the flexible battery can stretch up to 300 percent of its original size and still function.

Rogers, also a corresponding author of the paper, led the group that worked on the experimental and fabrication work of the stretchable battery. He is the Swanlund Chair at the University of Illinois at Urbana-Champaign.

Huang and Rogers have been working together for the last six years on stretchable electronics, and designing a cordless power supply has been a major challenge. Now they have solved the problem with their clever "space filling technique," which delivers a small, high-powered battery.

For their stretchable electronic circuits, the two developed "pop-up" technology that allows circuits to bend, stretch and twist. They created an array of tiny circuit elements connected by metal wire "pop-up bridges." When the array is stretched, the wires -- not the rigid circuits -- pop up.

This approach works for circuits but not for a stretchable battery. A lot of space is needed in between components for the "pop-up" interconnect to work. Circuits can be spaced out enough in an array, but battery components must be packed tightly to produce a powerful but small battery. There is not enough space between battery components for the "pop-up" technology to work.

Huang's design solution is to use metal wire interconnects that are long, wavy lines, filling the small space between battery components. (The power travels through the interconnects.)

The unique mechanism is a "spring within a spring": The line connecting the components is a large "S" shape and within that "S" are many smaller "S's." When the battery is stretched, the large "S" first stretches out and disappears, leaving a line of small squiggles. The stretching continues, with the small squiggles disappearing as the interconnect between electrodes becomes taut.

"We call this ordered unraveling," Huang said. "And this is how we can produce a battery that stretches up to 300 percent of its original size."

The stretching process is reversible, and the battery can be recharged wirelessly. The battery's design allows for the integration of stretchable, inductive coils to enable charging through an external source but without the need for a physical connection.

Huang, Rogers and their teams found the battery capable of 20 cycles of recharging with little loss in capacity. The system they report in the paper consists of a square array of 100 electrode disks, electrically connected in parallel.

### Huang's research was supported by the Initiative for Sustainability and Energy at Northwestern University (ISEN).

The paper is titled "Stretchable batteries with self-similar serpentine interconnects and integrated wireless recharging systems." In addition to Huang and Rogers, Yihui Zhang from Northwestern University is one of two co-first authors of the paper. Other authors include Yewang Su and Huanyu Cheng of Northwestern.

ELSE PRESS RELEASES FROM THIS DATE:

Cleveland Clinic study shows bariatric surgery restores pancreatic function by targeting belly fat

2013-02-26

In a substudy of the STAMPEDE trial (Surgical Therapy And Medications Potentially Eradicate Diabetes Efficiently), Cleveland Clinic researchers have found that gastric bypass surgery reverses diabetes by uniquely restoring pancreatic function in moderately obese patients with uncontrolled type 2 diabetes. The two-year substudy evaluated the effects of bariatric surgery and intensive medical therapy on blood sugar levels, body composition, and pancreatic beta-cell function. Striking metabolic changes were observed in patients who underwent bariatric surgery compared with ...

Light particles illuminate the vacuum

2013-02-26

The researchers conducted a mirror experiment to show that by changing the position of the mirror in a vacuum, virtual particles can be transformed into real photons that can be experimentally observed. In a vacuum, there is energy and noise, the existence of which follows the uncertainty principle in quantum mechanics. If we act fast enough, we can prevent the particles from recombining – they will then be transformed into real particles that can be detected', says Dr. Sorin Paraoanu from Aalto University. For the experiment, the researchers used an array of superconducting ...

Target: Cancer

2013-02-26

For scientists to improve cancer treatments with targeted therapeutic drugs, they need to be able to see proteins prevalent in the cancer cells. This has been impossible, until now. Thanks to a new microscopy technique, University of Akron researcher Dr. Adam Smith, assistant professor of chemistry, has observed how clusters of epidermal growth factor receptor (EGFR) — a protein abundant in lung and colon cancers, glioblastoma and others — malfunctions in cancer cells. "We can directly observe protein clusters, in a living cell membrane, that are invisible to traditional ...

Superbugs may have a soft spot, after all

2013-02-26

The overuse of antibiotics has created strains of bacteria resistant to medication, making the diseases they cause difficult to treat, or even deadly. But now a research team at the University of Rochester has identified a weakness in at least one superbug that scientists may be able to medically exploit. Biologists Gloria Culver at Rochester and Keith Connolly, now at Harvard University, thought one key to stopping the bacteria may lie with proteins, so they studied the mechanism behind the development of bacterial ribosomes—the cell's protein-manufacturing machine. ...

Gut microbiota plays important role in functional bowel disorders

2013-02-26

(24 February 2013) An estimated 50 per cent of patients consulting a gastroenterologist suffer from functional bowel disorders (FBD), such as dyspepsia or irritable bowel syndrome (IBS). It is characteristic for these conditions that underlying physiological mechanisms are hard to be found. "However, recent research shows that the gut microbiota is a likely candidate for filling some of the gaps in the causal chain leading to FBD," says Professor Fernando Azpiroz, Chairman of the Gut Microbiota & Health Section of the European Society of Neurogastroenterology & Motility ...

Fecal microbiota transplantation cures gastrointestinal diseases

2013-02-26

(26 February 2013) Clostridium difficile infections have developed into a virtual pandemic over the past two decades. The outcome of standard antibiotic treatment is unsatisfactory: the recurrence rates are high with every relapse increasing the risk of further follow-ups. Faecal microbiota transplantation offers a rapidly acting and highly effective alternative in treating recurrent Clostridium difficile infections (RCDI), as Professor Lawrence J. Brandt (Montefiore Medical Center, New York, USA) points out. According to him, more than 90 per cent of the patients are being ...

Survey shows medical students have frequent interactions with pharmaceutical companies

2013-02-26

Boston – A first-of-its kind national survey of medical students and residents finds that despite recent efforts by medical schools and academic medical centers to restrict access of pharmaceutical sales representatives to medical trainees, medical students and residents still commonly receive meals, gifts, and industry-sponsored educational materials. The study was completed by a team of researchers led by fourth-year Harvard Medical School student Kirsten Austad and Aaron Kesselheim, M.D., J.D., M.P.H., an internist and health policy researcher in the Division of Pharmacoepidemiology ...

An atlas of the human heart is drawn using statistics

2013-02-26

Researchers at Pompeu Fabra University (Spain) have created a high resolution atlas of the heart with 3D images taken from 138 people. The study demonstrates that an average image of an organ along with its variations can be obtained for the purposes of comparing individual cases and differentiating healthy forms from pathologies. "This atlas is a statistical description of how the heart and its components – such as the ventricles and the atrium – look," as explained to SINC by Corné Hoogendoorn, researcher at the CISTIB centre of the Pompeu Fabra University. Scientists ...

Infrared digital holography allows firefighters to see through flames, image moving people

2013-02-26

Firefighters put their lives on the line in some of the most dangerous conditions on Earth. One of their greatest challenges, however, is seeing through thick veils of smoke and walls of flame to find people in need of rescue. A team of Italian researchers has developed a new imaging technique that uses infrared (IR) digital holography to peer through chaotic conflagrations and capture potentially lifesaving and otherwise hidden details. The team describes its breakthrough results and their applications in a paper published today in the Optical Society's (OSA) open-access ...

Sweet news for stem cell's 'Holy Grail'

2013-02-26

Scientists have used sugar-coated scaffolding to move a step closer to the routine use of stem cells in the clinic and unlock their huge potential to cure diseases from Alzheimer's to diabetes. Stem cells have the unique ability to turn into any type of human cell, opening up all sorts of therapeutic possibilities for some of the world's incurable diseases and conditions. The problem facing scientists is how to encourage stem cells to turn into the particular type of cell required to treat a specific disease. But researchers at the University of Manchester's School ...

Clever battery completes stretchable electronics package

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: