Biomimicry inspires new kind of glass.

August 16, 2015 Biomimicry

A strange tiny animal, the microscopic tardigrade is the inspiration behind a new material that could improve the efficiency of products like LED lights and solar cells.

The material under investigation is glass, and tardigrades (sometimes known as “water bears” or “moss piglets”) appear specialists in its production. These water-dwelling micro-organisms, which resemble minute caterpillars with eight stubby legs, are capable of shedding almost all of the water in their cells when exposed to extreme conditions, such as heat, cold or even the vacuum of space.

“When you remove the water, they quickly coat themselves in large amounts of glassy molecules,” said Juan de Pablo, professor of molecular engineering at the University of Chicago and one of the authors of a recent study on the tardigrade-inspired glass.

The glassy molecules help the microscopic animals adopt a state of suspended animation as they float through harsh environments and the new glass they inspired was produced using a method known as physical vapor deposition.

This is a process in which the molecules that will make the glass are evaporated inside a vacuum and then left to condense, layer by layer, on top of a temperature-controlled substrate or support structure.

Analysis showed that in some areas within the new glass, the molecules were all oriented in the same way, and therefore interacted with light in a similar way.

Because the structure of glass is usually random, finding one of these materials that has most or all of its molecules orientated in the same direction is rare and is also really desirable for certain applications.

For example, when designing an LED, the goal is to get as much of the light that hits the surface to travel “up and away” from the substrate. Conversely, solar cell designers want as much light as possible to travel “down,” toward the substrate.

Until now, semiconductor researchers weren’t sure what caused the molecules in glass, in certain instances, to cooperate and point in the same direction. They assumed that certain glass molecules were just better at orienting themselves than others. But the new, tardigrade-inspired research suggests that isn’t the case.

Its early days but researchers see clear commercial applications for the new glass and now need to work out how to expand manufacturing scale from microscopic to mass production.