Hi, this is Wayne again with a topic “Stretchy, color-shifting materials”.
Benjamin MILLER, My name is Benjamin Miller., I’m a PhD candidate in the laboratory for bio-inspired photonic engineering here in Mechanical Engineering at MIT., And our group looks at how nature manipulates, color and also looking at how we can take those lessons and use them to produce new Materials and devices inspired by nature., Quite often in nature, color, is produced not through pigments or dyes, but a phenomenon known as structural color.. So this is how a lot of things like butterflies, bird feathers, for example, get their color. And in structural color you have nanoscale structures that interact with light causing it to reflect certain colors.. So for the past few years my research has been looking at. How can we create synthetic versions of materials like this that are also elastic If you make them elastic? It means that, as you stretch or compress them, the spacing of those little nanostructures changes in turn. Changing the color of light, that’s reflected.. So there are a lot of different ways to do this and there’s a lot of existing techniques., But a lot of them suffer from the problem: they’re, not necessarily scalable or they’re too expensive..
So what we were trying to do was develop a new technique that can solve those challenges.. So the starting point for the technique that we use is actually using holographic, recording material sort of thing. That’S used for anti-counterfeiting or passports for example., And then the manufacturing technique is actually really simple..
All we do. There is stick that basically to a reflective surface, so like a mirror or brushed aluminum a steel plate., And we expose that to light from a desktop projector.. We make a couple of slight modifications to it., But basically we stick this holographic material onto a reflector project, the light onto it, and it forms these nanoscale structures within that thin holographic film..
Once we’ve done that, we can bond that film to other materials, whether that’s textiles or thin sheets of black silicone.. At that point, it’s essentially a structural kind of material. And then, as we stretch it again, these nanoscale structures change in size changing the color of light. That’S reflected., So the first application that we’ve been looking at is actually to develop compression bandages..
So if we literally stick a thin sheet of this material onto a compression bandage, then the color of that bandage is a visual indicator of how much force you’re, applying as you wrap it around the leg.. So that means that essentially, physicians can apply pressure correctly. More often, but also potentially, that people could just do it at home on their own, maybe take a picture with their phone just to let them know if it’s done correctly. .