Search Bits: July 26

Optical computing with polarization

Researchers at the University of Oxford and the University of Exeter have developed a method that uses polarization of light To maximize information storage density and computing performance using nanowires.

The researchers note that the different polarizations of light do not interact with each other, which allows each to be used as an independent information channel. “We all know that the advantage of photonics over electronics is that light is faster and more efficient in large bandwidth. Therefore, our goal was to take full advantage of the advantages of photonics that combine with a tunable material to achieve faster and more intense information processing,” said Jun Sang Lee, a student DPhil in the Department of Materials at the University of Oxford.

They have developed a dielectric-active hybrid nanowire (HAD) using a hybrid glass material that exhibits the properties of switchable materials when illuminated by light pulses. Each nanowire exhibits selective responses to a specific polarization direction, so that information can be simultaneously processed using multiple polarizations in different directions. They said the new photonic design could be up to 300 times faster and denser than current electronic chips.

“This is just the beginning of what we would like to see in the future, which is to exploit all the degrees of freedoms that light offers, including polarization to dramatically balance information processing. Work is certainly in the early stages — still in the early stages,” said Harish Paskaran, professor of applied nanomaterials at the University of Oxford. Our estimates of velocity need to be investigated empirically — but they are very exciting ideas that combine electronics, nonlinear materials, and computing.

Harvesting energy from multiple sources

Scientists at Nanyang Technological University of Singapore (NTU Singapore) have developed a Stretchable and water repellent fabric Which converts the energy generated by the body’s movements into electrical energy.

While many energy-harvesting devices capture piezoelectric energy (when a material is compressed or crushed) or frictional electricity (when a material experiences friction with another), the new fabric can take advantage of both.

One of the main components of the fabric is a polymer that, when pressed or squeezed, converts mechanical stress into electrical energy. It’s also made with stretchable spandex as a base layer and integrated with a rubber-like material to keep it strong, flexible, and water-resistant.

A proof-of-concept experiment showed that a 3cm by 4cm piece of cloth generated enough electrical power to light 100 lights, or 2.34 watts per square meter of electricity. Washing, folding and wrinkling the fabric did not cause any performance degradation, and it could maintain a stable electrical output for up to five months.

“There have been many attempts to develop fabrics or garments that can harvest energy from movement, but the big challenge has been to develop something that does not deteriorate in function after being washed,” said Lee Pooi See, a materials scientist and associate professor at NTU. Excellent electrician. In our study, we showed that our prototype continues to function well after washing and curling. We believe it can be woven into shirts or incorporated into shoe soles to gather energy from the smallest movements of the body, and deliver electricity to portable devices.”

Lee continued, “Despite improved battery capacity and lower energy demand, power sources for wearable devices still require frequent battery replacements. Our results show that our model energy-harvesting fabric can harness vibration energy from humans to extend battery life or even to build systems that operate To our knowledge, this is the first perovskite-based hybrid power device that is stable, stretchable, breathable, waterproof and at the same time capable of delivering outstanding electrical output performance.”

simplify displays

Researchers from Stanford University, Lawrence Berkeley National Laboratory, and the University of Southern Mississippi suggest a way to make Stretchable color screens.

Zhitao Zhang, a postdoctoral researcher at Stanford University, found a yellow, light-emitting polymer called SuperYellow that became soft, pliable and also emit brighter light when mixed with a type of stretchable plastic polyurethane. “If we add polyurethane, we see SuperYellow nanostructures. These nanostructures are really important. They make the brittle polymer stretchable, and they make the polymer emit brighter light because the nanostructures are connected like a fishnet.”

The group then created red, green and blue light-emitting flexible polymers.

Combining different materials was a challenge. Zhenan Bao, a chemical engineer and professor at Stanford School of Engineering, said of the incorporation of materials, “Electronically, they have to match each other to give us high brightness. But then, they also need similar good mechanical properties to allow the screen to be stretchable. Finally, For manufacturing, Zhitao had to figure out a way to stack the layers together so that the process wouldn’t degrade the brightness.”

The final presentation has seven layers. Two outer layers are substrates that encase the device. Moving inward are two layers of electrodes, each following layers for charge transfer. Finally, the light-emitting layer is placed in the middle.

When electricity passes through the screen, one electrode injects positive charges into the light-emitting layer while the other injects negatively charged electrons into it. When these two types of charges meet, they bond and enter a state of active excitation. Almost immediately thereafter, the state returns to normal by producing a photon.

The team said the resulting polymer film could stick to an arm or finger and not break during bending or flexing. One of the applications will be wearable trackers whose screen is attached directly to the skin.