Category Technology/Electronics

Stretchy, Bendy, Flexible LEDs

They’re also cheaper, faster and fabricated with an inkjet printer.

Sure, you could attach two screens with a hinge and call a cell phone “foldable,” but what if you could roll it up and put it in your wallet? Or stretch it around your wrist to wear it as a watch?The next step in digital displays being developed at the McKelvey School of Engineering at Washington University in St. Louis could make that a reality.

First, there were light-emitting diodes, or LEDs. Then, organic LEDs, or OLEDs. Now, researchers in the lab of Chuan Wang, assistant professor in the Preston M. Green Department of Electrical & Systems Engineering, have developed a new material that has the best of both technologies and a novel way to fabricate it — using an inkjet printer.

The research was publis...

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Controlling Light with a Material Three Atoms Thick

Controlling Light With a Material Three Atoms Thick

Thin structures made of black phosphorus can tune the properties of light, with implications for science and technology. Most of us control light all the time without even thinking about it, usually in mundane ways: we don a pair of sunglasses and put on sunscreen, and close — or open — our window blinds.

But the control of light can also come in high-tech forms. The screen of the computer, tablet, or phone on which you are reading this is one example. Another is telecommunications, which controls light to create signals that carry data along fiber-optic cables.

Scientists also use high-tech methods to control light in the laboratory, and now, thanks to a new breakthrough that uses a specialized material only three atoms thick, they can control light more precisely than ever bef...

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A Wireless System based on Large-Area Electronics operating at Gigahertz Frequencies

A wireless system based on large-area electronics operating at gigahertz frequencies
Credit: Wu et al.

Large-area electronics (LAE) is an emerging technology for electronic device manufacture, such as printing or large-scale lithography, the process used to create flat panel displays and solar cells. Using LAE processes, engineers could create systems that are large (several square meters squared) and highly flexible; for instance, based on paper or plastic.

Over the past decade or so, many teams worldwide have been working on LAE systems. This has led to the creation of numerous innovative devices, such as large, flexible and sensing artificial skins for robots.

Researchers at Princeton University have recently realized a new wireless system based on LAE technology that can operate at gigahertz frequencies...

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Lightweight Electric Wristband Heaters for Constant, Portable Warmth

Infrared image of active wristband heater
An electrically conductive and durable yarn was sewn onto fabric and became a wearable heater (high temperatures indicated by yellows and reds) when a safe voltage was applied.
Credit: Adapted from ACS Applied Materials & Interfaces 2021, DOI: 10.1021/acsami.1c13329

As the fall chill settles in across the U.S., people are getting out their cozy sweaters and electric blankets, or stocking up on handheld heat packets for extra warmth. But sweaters and blankets are bulky, and heat packs only work for a little while. Now, researchers reporting in ACS Applied Materials & Interfaces demonstrate a conductive, durable yarn for lightweight wearable heaters that are re-usable and provide constant, portable warmth.

Lightweight wearable heaters with heating elements embedded within the fabric co...

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