Enzyme rich potato tissue can be used to cheaply and quickly mass produce bubble powered millimotors, new research shows.
Scientists have been developing synthetic self-powered motors over the last ten years after being inspired by the molecular motors that are ubiquitous in nature. These motors, including those responsible for the movement of flagella and cilia, power movement on a micro-scale by utilising fuels present in their surrounding environment.
Synthetic bubble propelled micromotors are traditionally built by coating one half of a tiny pellet with a metal catalyst or enzyme which, when placed in a solution of hydrogen peroxide, catalyses oxygen production to form streams of bubbles. This asymmetric production of bubbles, propels the pellet through the liquid.
Potatoes are rich in catalase, an enzyme commonly used in bubble powered micromotors. This led Joseph Wang from the University of California, US, and his colleagues, back to nature to make bubble powered millimotors in a beautifully simple manner. One half of a 2 x 1 mm potato cylinder is capped with epoxy, to mimic the asymmetric design of traditional micromotors. The catalase in the exposed potato tissue catalyses bubble production and propels the potato pellet at speeds of up to 5.12 mm s-1.
Wang says using natural tissues to make biomotors analogous to artificial bubble propelled motors makes a unique contribution to the field by ‘closing the loop’ with nature. Using catalase in its natural environment and most stable form is a major benefit of the system and also avoids expensive purification procedures. At current prices, over 500,000 potato motors could be made for only $1 (66p).
Steve Ebbens, an expert in nanoswimming devices at the University of Sheffield, UK, is impressed by this approach because it neatly avoids the technically difficult step of coating enzymes onto motor pellets which often results in reduced enzyme activity.
In the future, the team plan to develop these motors in synergy with other self-propelled motors they have designed. They also hope to utilise other enzyme rich tissues to take advantage of the wide range of fuels available in the natural environment.