A team of scientists at the Massachusetts Institute of Technology has discovered a novel, ‘chameleon’ material capable of changing the colour of medical bandages that could help doctors identify issues more quickly.
The MIT researchers applied a 19th Century colour photographic effect on holographic materials which allowed them to print large-scale images onto elastic materials that, when stretched, could change their colour, reflecting different wavelengths as the material is put under stress.
The team used Lippmann photography – a colour photography technique invented by physicist Gabriel Lippmann, who later won the Nobel Prize in Physics for the technique – which propels light onto a mirror behind a very thin, transparent emulsion created using tiny light-sensitive grains, which, over time, reconfigured to create an image. However, the process was laborious and fell out of favour until Dr Miller tried to speed up the process using modern methods.
The result is the potential for anything from colour-changing bandages to stretching film to reveal a hidden message. Associate Professor of Mechanical Engineering, Mathias Kolle, part of the MIT team, said: “The chemistries of these modern holographic materials are now so responsive that it’s possible to do this technique on a short timescale simply with a projector.”
Another member of the MIT team, Dr Benjamin Miller, added: “Now that we’ve cleared this scaling hurdle, we can explore questions like: Can we use this material to make robotic skin that has a human-like sense of touch? And can we create touch-sensing devices for things like virtual augmented reality or medical training? It’s a big space we’re looking at now.”
The team is now actively looking at potential uses of the research that could lead to colour-changing bandages for use in monitoring bandage pressure levels when treating conditions such as venous ulcers and certain lymphatic disorders.