A new display technology: Spots of innovation

Magnetic microspheres could have a range of colourful applications A FEW years ago Yadong Yin was experimenting with tiny beads that changed colour when a magnetic field was applied to them. This was interesting but, as the beads floated around in water with no obvious way to turn them into a product, people asked: What could be done with them? Now Dr Yin and his colleagues at the University of California, Riverside, have carried out more experiments and have come up with possible applications that range from a new type of paint to lipsticks and giant advertising billboards. Dr Yin’s beads are magnetochromatic microspheres. They are made from tiny blobs of polymer that contain particles of iron oxide. The structure of these particles changes in a magnetic field in a way that produces “interference” colours when light is shone on them. Interference, in which fine details on an object’s surface cause light waves to cancel each other in some places and reinforce one another in ... (link)