Image of the Week - 03 August 2004

Water Droplet on PDMS

Changing the surface features of poly(dimethylsiloxane) (PDMS) changes the angle that the water makes with the surface. The PDMS used in this photo has been patterned with a grid of 100 um^2 dots, seen here as blue circles, magnified and slightly distorted by the curvature of the droplet.
The photo was acquired in the VMIL by the Canon EOS-1Ds on a Manfrotto tripod mount using the 5x macro lens at almost maximum magnification. The PDMS sample was placed upon a blue gel laid on top of a lightbox, which provided a diffuse illumination for the entire sample. Two macro flash units were positioned approximately 15cm from the PDMS in order to provide sufficient light for a short exposure time. (The bright white specular reflections are a result of the macro flash.)

Image Courtesy: Michael Motala - Department of Inorganic Chemistry, Dr. Ralph Nuzzo - Director, Materials Research Laboratory

Contact: mmotala@uiuc.edu