la061165+_si_003.mpg (934.29 kB)
Reversible Pattern Formation through Photolysis
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posted on 2006-08-15, 00:00 authored by Timothy R. Kline, Ayusman SenWe report a photolytic method to induce spatial and temporal patterning/deposition of particles at the micron scale
on a time scale of seconds. Reversible pattern formation by negatively charged particles occur around micron-sized
silver features on different substrates when exposed to UV light in the presence of aqueous hydrogen peroxide.
Diffusiophoretic motion due to a spatially defined ion gradient accounts for our observations. Atomic force and optical
microscopy, as well as conductivity measurements, support this hypothesis.