Modeling and Analysis of a Microfluidic Capillary Valve

Date

2017-04-01

Author

Yıldırım, Ender

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

117
views

0
downloads

Here, a numerical model for analysis of a capillary valve for use in microfluidic devices was presented. Capillary valves are preferred especially in passive microfluidic systems, where the capillary forces dominate the liquid motion, to manipulate the flow. The capillary valve in this work, was formed by the sudden expansion of a rectangular microchannel to an opening, whose depth and width are larger than the height and the width of the channel respectively. Noting that there was no available analytical model to determine the pressure capacity of such valves, a numerical model based on energy minimization was utilized. Free software Surface Evolver was used to solve the model. Dependence of the pressure capacity on the contact angle of the working liquid on the channel material was investigated. It was found that the pressure capacity of the valves would be maximum if the contact angle on all surfaces is 90 degrees. Accordingly, the valves could withstand approximately 2.5 kPa for 100 mu m x 100 mu m channels when the contact angle was 90 degrees. The model was verified by comparing the results with those available in the literature.

Subject Keywords

Microfluidic, Capillary valve, Pressure capacity, Contact angle

URI

https://hdl.handle.net/11511/46775

Journal

Politeknik Dergisi

DOI

https://doi.org/10.2339/2017.20.2

Collections

Department of Mechanical Engineering, Article

Suggestions

OpenMETU
Core

Computational elastodynamics of functionally graded thick-walled cylinders and annular coatings subjected to pressure shocks Abeidi, Abdelrahim; Dağ, Serkan (2022-12-01) A computational technique based on domain-boundary element method (D-BEM) is developed for elastodynamic analysis of functionally graded thick-walled cylinders and annular coatings subjected to pressure shock type of loadings. The formulation is built on the wave equation, which is derived in accordance with plane elastody-namics. Weighted residual statement for the wave equation is expressed by using the static fundamental solution as the weight function. Applying integration by parts and incorporating the...
Modeling of localization and necking in dual phase steels through polycrystalline plasticity Çakmak, Serhat Onur.; Yalçınkaya, Tuncay; Department of Aerospace Engineering (2020) In this thesis, the effect of ferrite crystallographic orientation distribution and other microstructural parameters such as martensite morphology, martensite volume fraction, and ferrite grain size on the plastic deformation, localization, and the necking behavior of dual-phase steels are investigated. Two different type of finite element models, i.e. full size micron-scale polycrystalline samples and polycrystalline Representative Volume Element (RVEs) are built through Voronoi tessellation. Local crystal...
Numerical and experimental investigaton of ultrasonic embossing technique for fabrication of thermoplastic microfluidic devices Çoğun, Ferah; Arıkan, Mehmet Ali Sahir; Yıldırım, Ender; Department of Mechanical Engineering (2018) In this study, numerical models and experimental results were presented to describe mechanisms of hot embossing (HE) and ultrasonic embossing (UE) for fabrication of thermoplastic microfluidic chips. The substrates were embossed using micromilled aluminum molds in both techniques. Effects of embossing temperature, time, and force on performance outputs (replication rates and channel symmetry) were investigated numerically and experimentally in HE. Experimental results revealed the importance of temperature ...
Optimization of Hot Embossing Process for Fabrication of Microfluidic Devices Ziyara, Abbas; Çoğun, Ferah; Varol, Ceren; Totuk, Onat Halis; Yıldırım, Ender (2015-05-14) This paper presents a low cost hot embossing press and optimization of the process parameters for fabrication of microfluidic chips. For testing purposes, we fabricated a mold made of brass using micro milling process. By utilizing Taguchi method we found that 200 µm wide channels on polymethylmethacrylate (PMMA) substrates can be obtained by applying 240 bars for 6 min. under 180oC. Total cycle time per one chip is measured as 11 min.
Modeling the effect of key cathode design parameters on the electrochemical performance of a lithium-sulfur battery Erisen, Nisa; Emerce, Nur Ber; Erensoy, Sevgi Can; Eroglu, Damla (2018-06-25) A 1D model is developed for the Li-S cell to predict the effect of critical cathode design parameterscarbon-to-sulfur (C/S) and electrolyte-to-sulfur (E/S) ratios in the cathodeon the electrochemical performance. Cell voltage at 60% depth of discharge corresponding to the lower voltage plateau is used as a metric for calculating the cell performance. The cathode kinetics in the lower voltage plateau is defined with a single electrochemical reaction; thus, the model has a single apparent kinetic model parame...

Citation Formats

E. Yıldırım, “Modeling and Analysis of a Microfluidic Capillary Valve,” Politeknik Dergisi, pp. 487–494, 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46775.