Reversible Pattern Formation through Photolysis

2006-08-15T00:00:00Z (GMT) by Timothy R. Kline Ayusman Sen
We 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.