Home Stretchable Batteries Could Power Devices Embedded In The Body [Video]

Stretchable Batteries Could Power Devices Embedded In The Body [Video]

Two years ago, Nokia made waves when it displayed a concept phone using a flexible OLED display. Samsung and Ericsson have shown similar prototypes. So

flexible devices

and displays are on the market horizon. But they’re still just a first step toward a new class of future devices that can not just flex, but actually stretch – so they can be safely and comfortably implanted in the body, for example.  

So what is the prognosis for these “stretchable” devices? One piece of the puzzle has recently been developed in a partnership between Northwestern University and the University of Illinois: a

stretchable lithium-ion battery

The “Stretch Armstrong” of Batteries 

It took Yonggang Huang and John A. Rogers, from Northwestern and University of Illinois, respectively, six years to develop a cordless power supply that was versatile enough to be used in stretchable electronics, particularly devices used inside the human body.

Finally, they were able to come up with “pop-up” technology that allows the circuits to bend and twist. Typically, circuits inside of batteries are rigid, but creating bridges using metal wiring to connect the elements gives the circuits the ability to stretch and flex along with any device. The power in the metal bridges works its way through the circuits to power the battery. 

In a video (below), Huang and Rogers demo the battery by hooking it up to an LED light and slowly stretching it out. The battery was able to reach about 300% of its original size and still provide power. Once stretched, the battery can regain its original size without damage to the circuits. 

Its life span is about 20 charging cycles – and it can be recycled just like any other lithium-ion battery. Due to its small size, it can hold a charge for only eight to nine hours, but the battery charges wirelessly using coils that induce charging through an external source. This makes it ideal for use in medical devices embedded in the body. 

‘Flexible’ And ‘Stretchable’ Are Distant Cousins 

It seems like a stretchable battery would be attractive for the flexible device market, but Huang says the two aren’t as alike as one would think. In an email to ReadWrite, Huang said that while the OLED displays from Nokia and Samsung are


, they aren’t



“Flexible means the device could be bent or twisted, which essentially requires the device to be very thin. Stretchable represents a more challenging type of mechanics, which requires that the device must accommodate a large strain deformation, including not only bending, twisting, but also stretching and compressing.” 

The two could possibly go hand in hand, say in a nifty

new watch design

from a well known tech giant, but successful flexible devices will require more than mere flexibility. As mobile devices become more and more like physical attachments, they will have to move like our own skin, stretchy



A report from

Bloomberg News about the possible Apple iWatch

says that it may take about three years to be able to develop glass flexible enough to curve or even wrap around someone’s wrist. While Apple and others work on making flexible mobile devices a reality, they may also want to take a look at adding some stretchiness to the product development. 

Image courtesy of Northwestern University.

About ReadWrite’s Editorial Process

The ReadWrite Editorial policy involves closely monitoring the tech industry for major developments, new product launches, AI breakthroughs, video game releases and other newsworthy events. Editors assign relevant stories to staff writers or freelance contributors with expertise in each particular topic area. Before publication, articles go through a rigorous round of editing for accuracy, clarity, and to ensure adherence to ReadWrite's style guidelines.

Get the biggest tech headlines of the day delivered to your inbox

    By signing up, you agree to our Terms and Privacy Policy. Unsubscribe anytime.

    Tech News

    Explore the latest in tech with our Tech News. We cut through the noise for concise, relevant updates, keeping you informed about the rapidly evolving tech landscape with curated content that separates signal from noise.

    In-Depth Tech Stories

    Explore tech impact in In-Depth Stories. Narrative data journalism offers comprehensive analyses, revealing stories behind data. Understand industry trends for a deeper perspective on tech's intricate relationships with society.

    Expert Reviews

    Empower decisions with Expert Reviews, merging industry expertise and insightful analysis. Delve into tech intricacies, get the best deals, and stay ahead with our trustworthy guide to navigating the ever-changing tech market.