Evolutionary advance
For many millions of years, life on earth has evolved complex structures, successfully adapting to diverse environments. Biomimetics, the replication of biological designs, is now exploring the use of living cells to create innovative materials for commercial purposes.

The research into evolution by Professor Andrew Parker, from Green College Oxford, UK, has inspired some new thinking about manufacturing techniques. ‘When I discovered that nature has superior designs to what we were producing already in commerce,’ says Parker, ‘it seemed obvious that industry would be interested, and they were.’

His team, based at the Natural History Museum and the University of Oxford, has discovered several examples of where living cells can be used in manufacturing, for example a plant-like marine organism whose iridescent shell could be harvested and mixed into paints, cosmetics and clothing to create stunning colour-changing effects, or embedded into polymers to produce holograms that are difficult to forge.

Optical effect
The tiny single-celled 'diatom' evolved millions of years ago. Its hard silica shell displays vivid colours that change depending on the angle at which it is observed. A network of tiny holes in its shell interferes with light waves to create the shimmering effect.

Manufacturing products with this iridescent property is expensive and energy-intensive. ‘Maybe’, says Professor Parker, ‘we can't produce this in industry using current manufacturing techniques, but the organism is making it efficiently itself, at room temperature and low pressures, and using a process that has a low carbon footprint, so let’s see if we can copy that process.’

He continues, ‘the diatom’s silica shell is the iridescent device itself. We can culture these cells easily and kill off the living material, leaving the iridescent devices.’

Biodegradable advantage
The structure of a fly’s eye provided another inspiration. Professor Parker explains, ‘if you look into a glass window you see a reflection of yourself. If you put the fly's eye surface onto the window you no longer see your reflection because all the light passes through. This is good for the fly because it means that in low light levels it collects all the light through its eye. No light is lost through reflection. It seemed an obvious application for solar panels.’

He continues, ‘Nature's nanotechnology is designed to be biodegradable whereas human nanotechnology is the opposite.’ Another reason to take inspiration from nature.