Tiny robots made using pollen could one day be used to clean contaminated water.
Waste water from some factories contains mercury, a聽metal that can cause illness if consumed. There are techniques to remove mercury in water treatment plants, but they are time consuming and expensive.
Martin Pumera at the University of Chemistry and Technology, Prague, in the Czech Republic, and his colleagues are working on a low-cost alternative. Some pollen grains have a natural tendency to adsorb mercury, so Pumera and his team are experimenting to find ways to turn the grains into tiny mercury-removing robots.
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鈥淧ollen is highly stable and we can have it in kilogram quantities very cheaply,鈥� says Pumera.
The researchers used pollen from a range of plants, including dandelion, pine, lotus, sunflower, poppy, camellia, lycopodium and cattail. They first cleaned and purified pollen, then attached particles of platinum to just one side of each pollen grain.
They added the modified pollen to water contaminated with 0.2 per cent mercury by mass. They also added hydrogen peroxide to the water, which reacts with the platinum to form a chemical motor that helps the microrobots travel faster.
After two hours in solution, every type of pollen had adsorbed at least 80 per cent of the mercury. Grains from a lotus flower had the highest velocity in the water 鈥� about 78 centimetres per hour 鈥� while cattail adsorbed the most mercury 鈥� around 90 per cent.
鈥淲e are now working on enzymatically powered microrobots,鈥� says Pumera.
Advanced Functional Materials
