Design and fabrication of a chaotic mixer for BioMEMS applications

Since fabrication of microchips by MEMS technology has emerged, microchips that can interact with biological samples like virus, bacteria, DNA has been developed. Considering the advantages such as cost, dimension and compatibility with IC fabrication, these chips have found specific application areas. Microfluids and microfluidics constitute one of the major research areas of this emerging field, BioMEMS. Micro mixers have become an important component of BioMEMS which are designed for microfluidics applications. Fluids demonstrate two types of flow regime, laminar and turbulent. Turbulent flow is more advantageous than laminar flow when mixing is considered. Creating turbulent flow within microchannels, commonly used in BioMEMS devices, is a challenging task as scaling into the micro domain causes fluids to mix solely by diffusion. This study presents a method for mixing in micro environment based on chaotic advection. The proposed micro mixer makes use of the turbulent flow induced by bubbles which are created by thermal actuation based on joule heating principle on gold electrodes.