Microfluidics Research

54th Annual Meeting of the Division of Fluid Dynamics

November 18 - 20, 2001, San Diego, California
Session JQ. Microfluid Devices V: Experiments

Monday afternoon, 15:10, Marriott Hall 4, Marriott Hotel and Marina San Diego

Nari Soundarrajan, Carl Meinhart, Igor Mezic (University of California, Santa Barbara CA)

Abstract (copy)

Flow visualization experiments are presented to validate numerical studies of fluidic mixing in micro channels. Mixing is achieved in a laminar flow by perturbing the main flow with transverse impinging jets from secondary side channels. This stretches and folds the layers in the flow stream causing chaotic advection, thereby increasing mixing. The current mixer is a silicon etched device with a glass cover slip anodically bonded on top to hermetically seal the chip. The main channel is 100\mum wide x 50\mum deep x 650\mum long. Experiments were performed by oscillating the flow through the first pair of secondary side channels using a specially developed oscillating syringe pump. The oscillating flows in the side channels are driven with syringes connected to an actuator that has a sinusoidal motion. The working fluid consisted of fluorochrome Acridine Orange solution in water in one half of the main channel cross section and plain DI water in the other. The time evolution of the flow is observed using an epi-fluorescent microscope and a high speed CCD camera. The resulting images are used to characterize the mixing in the flow.