Valve-less rectification micropumps based on bifurcation geometries
Micropumps are key components in many Microsystems such as Lab-On-a-Chip (LOC) and Micro Total Analysis Systems (μTAS). An efficient, bidirectional, and multifunctional micropump is important to enhance the overall efficiency of any microsystem with fluid flow. Developing a bidirectional micropump with pumping and mixing capabilities will advance microsysetems technology and aid in fabricating more compact microsystems. ^ In this work, a valve-less rectification micropump based on bifurcation geometry is designed, fabricated, and tested. Three different designs were experimentally investigated. Numerical investigation based on Lattice Boltzmann Method (LBM) was employed prior to the experimental work to numerically measure the microfluidic diodicity in conventional and non-conventional geometries at low Reynolds numbers. Sofllithography and optical lithography were used to fabricate the micropumps. The working fluid and actuator were chosen to be ethanol and PZT, respectively. Moreover, the effect of the fabrication material on the micropump efficiency was investigated where two micropumps were fabricated from two different materials, PDMS and SU-8, and the testing results were compared. ^ Additionally, the concept of valve-less rectification micropump based on a dynamic rectifying geometry was tested and verified. The results confirm the feasibility of the valve-less rectification micropump based on bifurcation geometry. Since streaming flow occurs in bifurcation structures when oscillatory flow in presence, the results of this work will lay the foundations for a micrcofluidic device that can perform two functions (bidirectional pumping and Mixing), generate streaming flow at zero-mean velocity, reliable, easy to fabricate, cost effective, compatible with wide range of working fluids and materials, capable of delivering particles-laden fluids, and self priming. ^
Applied Mechanics|Engineering, Mechanical
"Valve-less rectification micropumps based on bifurcation geometries"
Dissertations and Master's Theses (Campus Access).