A Natural Transparent Display

By Tom Allen

Scientists at MIT and Harvard University may have found the ‘key’ to next-generation augmented reality displays – on the shell of a European mollusc.

The blue-rayed limpet is a small shellfish living in kelp beds, primarily in the North Sea. It is distinguished by bright blue dotted lines running in parallel along its shell. The researchers have identified two optical structures in the shell that provide the blue-striped appearance, which can be very bright when hit by angled light. It is the first evidence of an organism producing optical displays using mineral structures, rather than organic structures (like feathers).

It is thought that these natural optical structures could be used as a basis for developing colour-selective, controllable transparent displays, which do not require an internal light source and could be incorporated into glass and windows.

Mathias Kolle of MIT said, “We believe that the limpet’s approach to displaying colour patterns in a translucent shell could serve as a starting point for developing such [transparent] displays”.

The zig-zag pattern acts as a filter, reflecting only blue light. Other light passes through the translucent shell and is absorbed by underlying particles, increasing the blue light’s vividness.