GLASS SURFACE

1. Vdrive GLASS SURFACE Liquid behavior within micro-channels and on surfacesBruce M. Law, Kansas State University, DMR 0603144 Microfluidics uses micron-sized channels to create a chemical factory on a “chip”, the size of a credit card. Liquids are propelled along these channels and where two channels meet, a chemical reaction can occur. Understanding how liquids slip on solid surfaces is very important in microfluids. To study liquid slip one can (a) examine liquid filament breakup into liquid droplets(in V-shaped channels) (Langmuir 23, 12138 (2007)) or (b) study liquid expulsion from between a spherical surface and flat surface using “colloidal probe Atomic Force Microscopy” (Phys. Rev. E 80, 060601(R) (2009)). The greater the liquid slip the more readily these two solid surfaces approach each other. This work has improved our understanding of liquid hydrodynamics on nanometer length scales. b)

2. Liquid behavior within micro-channels and on surfacesBruce M. Law, Kansas State University, DMR 0603144 Undergraduate Frank Male has spent the last 3 summers collaborating with Dr Martin Brinkmann at the Max Planck Institute for Dynamics and Self-organization in Goettingen, Germany. Frank has been simulating the break-up of liquid filaments into liquid droplets in V-shaped channels. This work is directly related to the experimental work in (a) on the preceding slide. The picture opposite shows a 2D cross-section of the forces and velocity flows that are present in a V-shaped channel as an initial liquid/vapor perturbation relaxes. Frank is currently comparing these simulations with experimental data in order to extract out the liquid slip behavior. 2D cross-section of forces (red arrows) and velocities (blue arrows) as a liquid/vapor perturbation relaxes in a V-shaped channel.