Sunday October 06, 2013
This is a bit of clear rubbery silicone with a gold-coated hologram on the top. The patterns are little microchannels where liquid can flow across the surface of the silicone; the larger round areas are where hollow needles can be poked in from the other side of the silicone to inject the liquid. Our lab built this device for use as a chemical sensor; it turns out that when chemicals stick to the rainbow surface of the hologram, the rainbow pattern shifts slightly. By treating the hologram surface so that only certain chemicals can stick to it, we can look for the presence of just those chemicals.
Photo taken with my new easy-macro lens, plus an iPhone camera. The easy-macro lens is just a little plastic lens on a rubber band, but it lets me detect features as closely separated as 50 micrometers - pretty impressive!