In the magazine “Science”, a weird little “worm” appeared, twisting and flashing lights at the same time.
In fact, this is the research result demonstrated by Shepherd’s research group at Cornell University—a soft, luminous new material.
Soft, elastic, and luminous
Flexible materials must not only be “flexible and stretchable”, but also have enough ductility to not be damaged when stretched or kneaded. Moreover, the flexible materials used on robots must be able to complete a series of tasks, such as serving as “artificial skin” “To sense external stimuli, use light to transmit information, etc.
In the past, we have had some flexible materials, such as organic light-emitting diodes (OLEDs) that can change the display from straight to curved, but there are still some shortcomings. The elasticity and ductility of LED-type materials are still very low, and good records can only stretch 1.2 times.
Flexible LED device demonstration (picture from wikipedia)
Can a new material be made that is softer, more elastic, stretchable and functional? This time, researchers have designed a special “luminous skin” material, and the weird “luminous worm” in the picture above is a demonstration of this new technology.
This kind of material is very flexible and will not be damaged even if it is ravaged by others, and it can still maintain stable light emission. Under the influence of external force, the researchers can even stretch these soft light-emitting components to 4.8 times their original length, at which time they can continue to emit light.
If you combine the light-emitting elements one by one, they can also form a light-emitting array and still perform well. Through the control of the circuit, the pattern displayed by the luminous dot matrix can be easily controlled, and the light spots remain as stable as a mountain even after the researchers kneaded, stretched, and folded them.
Gel resin “sandwich”
How are these soft light-emitting components made? It is actually a “sandwich” structure made of multiple layers of materials, including silicone resin, polyacrylamide-lithium chloride hydrogel, zinc sulfide silicone resin, etc.Success.
Sandwich structure formed by silicone, polyacrylamide-lithium chloride hydrogel and zinc sulfide silicone (luminous core structure) (picture from original paper)
Silicone is an insulating material that is both malleable and transparent, and incorporating zinc sulfide can turn it into a light-emitting element that emits fluorescence under the action of an alternating electric field. The polyacrylamide-lithium chloride hydrogel forms a conductive interlayer, leaving a path for applying voltage. By adjusting the luminescent components, different luminescent colors can also be obtained: adding 0.01% copper, it can appear green; adding 0.1% copper, it can appear blue; and if adding 1% Manganese will appear yellow.
The more you poke the light, the brighter it becomes
In addition to Q-bombs and luminescence, this sandwich has another special feature: it can respond to external pressure and reflect light of different intensities. If you poke a flexible material with your finger, the harder you poke it, the greater the local stretch will be, and the stronger the light will be.
Poke it, the material not only has excellent ductility, but also becomes brighter (picture from the original paper)
This is because, as the material stretches, it becomes thinner overall and the spacing in the capacitor layers becomes smaller. When the voltage is kept constant, the electric field will be enhanced, so the electroluminescence will also be enhanced. Although the expansion of the luminescent interlayer will reduce the density of zinc sulfide in it, this effect is relatively small, so as the luminescent interlayer expands, the brightness will increase.
Combining these characteristics, we get the magical “worm” we saw at the beginning. The research team combined four layers of luminous interlayer materials and two layers of aerodynamic interlayers from top to bottom to obtain this colorful dazzling little worm. By inflating and deflating the pneumatic interlayer, the little bug squirms forward, and the light on its body also flashes bright and dark as the degree of inflation changes.
At the current research stage, this material still has shortcomings such as insufficient luminous brightness and high operating voltage. However, I believe that with the improvement of technology, this Q-bomb silicone “bug” can be used in more fields. Maybe it will become the “skin” on robots in the future.
Extended reading: https://www.alltextile.cn/product/product-99-902 .html
Extended reading: https://www. yingjietex.com/product/Nylon-twill-with-breathable-coat-Fabric.html
Extended reading:https://www.yingjietex.com/product/800D-120D-Polyester-Dobby-OXFORD-Fabric.html
Extended reading:https://www.tpu-ptfe.com/post/3320.html
Extended reading:https://www.yingjietex.com/product/polyester-Printing-fabric.html
Extension Reading: https://www.alltextile.cn/product/product-12-607.html
Extended reading: https://www.china-fire-retardant.com/post/9655.html
Extended reading: https://www.alltextile.cn/product/product-14-574.html
Extended reading: https://www.alltextile.cn/product/product-22-155.html
Extended reading:https://www.alltextile.cn/product/product-4-104.htm
