While most of us think of dusting as a simple matter of wiping with a damp cloth, Patrick F. Dunn, professor of aerospace and mechanical engineering at Notre Dame, says removing micro-particles from a surface can be much more difficult because the attraction forces are magnified at small scales. The example he gives is of erasing pencil marks from paper. After rubbing a mistake with an eraser, you can blow away most of the bits of rubber. Smaller pieces may require a wipe of the hand. But to extract the smallest pieces from the paper fibers may require gusts at supersonic speeds.
Often micro-particle-removal systems rely on electrostatic attraction, as in the recently introduced Swifter and other brand dusting wands. The cleaning cloths for these are electrostatically charged. This attracts the dust to the duster in a manner similar to how a photocopier transfers the black powder of toner onto specific regions of paper.
Dust removal has many other potentially important applications. Dunn says a colleague of his at the California Institute of Technology is working on system that can remove and analyze dust from luggage and parcels. In Sherlock Holmes fashion, micro-particles can give important clues about where an object has been. It turns out that some of the most difficult particles to extract from a surface are those of bomb-making materials.
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