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Flexible Mobile Devices Get a Flexible Battery Made From Nanotubes

Using standard electrochemical processes, carbon nanotube-enabled flexible battery can be made to any size

2 min read
Flexible Mobile Devices Get a Flexible Battery Made From Nanotubes
Photo: NJIT

After years of promises that mobile phones were going to become flexible, Samsung announced plans last month to release its flexible phone.

While the Samsung Galaxy Round is not flexible to the extent you can bend it to your heart’s content, it does offer a display that is flexible enough for the manufacturer to curve it. The move has also spurred other mobile device manufacturers to announce their intentions to market similar devices.

With the age of flexible devices seemingly upon us, one of the primary challenges for their development has been the power source. Samsung’s new phone is more or less powered by a standard rigid battery. But both LG and Samsung acknowledged that they are on a quest to develop a flexible battery that will enable a truly flexible phone.

Researchers, who anticipated that the launch of flexible mobile devices would require a flexible power source, have steadily pursued the flexible battery. There have been a few commercial efforts using printed electronics, and some thin-film technologies that have made a splash.

Now researchers at the New Jersey Institute of Technology (NJIT) have developed a flexible battery made from carbon nanotubes that is aimed at powering flexible devices. 

Over four years ago, researchers at Stanford University and the University of California, Los Angeles reported details of their efforts to use carbon nanotubes to produce flexible batteries through printed electronic techniques. The NJIT researchers avoided printed electronics and simply created a flexible material through standard electrochemical architectures, consisting of an electrode and an electrolyte. The carbon nanotubes and other microparticles used in the flexible material serve as active components of the battery such as the positive and negative material as well as the electrolyte.

“This battery can be made as small as a pinhead or as large as a carpet in your living room,” says Somenath Mitra, a professor of chemistry and environmental science at NJIT whose research group invented the battery. “So its applications are endless. You can place a rolled-up battery in the trunk of your electric car and have it power the vehicle.”

One of the distinguishing features of this technology, according to Mitra, is that consumers can fabricate it at home. Presumably one would buy a kit consisting of electrode paste and a laminating machine. To make the battery, you would coat two pieces of plastic with the electrode paste and then place a third plastic sheet between the two coated sheets. Then the assembly would be laminated together.

That feature is not likely to win the favor of companies like LG and Samsung as they seek out their solutions to the flexible battery issue. But it could make DIYers pretty pleased.

Photo: NJIT

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Deep Learning Could Bring the Concert Experience Home

The century-old quest for truly realistic sound production is finally paying off

12 min read
Image containing multiple aspects such as instruments and left and right open hands.
Stuart Bradford

Now that recorded sound has become ubiquitous, we hardly think about it. From our smartphones, smart speakers, TVs, radios, disc players, and car sound systems, it’s an enduring and enjoyable presence in our lives. In 2017, a survey by the polling firm Nielsen suggested that some 90 percent of the U.S. population listens to music regularly and that, on average, they do so 32 hours per week.

Behind this free-flowing pleasure are enormous industries applying technology to the long-standing goal of reproducing sound with the greatest possible realism. From Edison’s phonograph and the horn speakers of the 1880s, successive generations of engineers in pursuit of this ideal invented and exploited countless technologies: triode vacuum tubes, dynamic loudspeakers, magnetic phonograph cartridges, solid-state amplifier circuits in scores of different topologies, electrostatic speakers, optical discs, stereo, and surround sound. And over the past five decades, digital technologies, like audio compression and streaming, have transformed the music industry.

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