Chemical propulsion opens up new method for controlling microstructures

Previously, most research seeking to influence the direction of motion of microscopic components have had to use outside influences such as a magnetic field or the application of light.

The Warwick team have now found a way to do it by simply adding a chemical in a specific spot and then watching the microscopic matchstick particles move towards it, a phenomenon called chemotaxis.

The research, published in Materials Horizons (RSC) in a paper entitled Chemotaxis of catalytic silica–manganese oxide ‘matchstick’ particles, found that by adding a small amount of a catalyst to the head of a set microscopic rods, they could then cause the rods to be propelled towards the location of an appropriate ‘chemical fuel’ that was then added to a mixture.

For the purposes of their experiment the researchers placed silica–manganese oxide ‘heads’ on the matchstick material and introduced hydrogen peroxide as the chemical fuel in one particular place. They placed the ‘matchsticks’ in a mixture alongside ordinary polymer microspheres.