Traveling Wave Dielectrophoretic Pump for Blood Delivery

• Main Authors: Ching-Wen Huang, 黃敬文
• Other Authors: 李雨
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/58186380680708334334

碩士 === 國立臺灣大學 === 應用力學研究所 === 96 === This thesis studies experimentally the traveling wave dielectrophoretic pump for delivering two-phase suspension medium, using human blood as an example. The pump is essentially a rectangular straight micro channel with a crosstie type electrode array built on one wall and operated under ac voltage with phase shift at neighboring electrodes. Both the conventional and traveling wave dielectrophoresis are generated. The negative conventional dielectrophoretic force repels the red blood cells from the electrode surface and the traveling wave dielectrophoretic force drives the cells along the direction of increasing phase. As the cells move, they drag their neighboring fluid (plasma), and the whole blood is delivered, after some sophisticated interaction of dielectrophoresis and fluid mechanics. The pump was fabricated using MEMS techniques and tested with different parameters of experiment, including the applied voltage, the operating frequency, the phase shift between neighboring electrodes, the number of electrodes, the dimensions of the channel, and the type of enhanced electrodes. It is found that the pump can attain a maximum pumping velocity at an intermediate frequency (about 20 MHz) and channel height (about 40 μm) with four phase signals. The steady average cell velocity can attain 15 μm/s for a pump with 1mm length and 24 electrodes, and operated with a four phase signal at 5 volts and 20 MHz. The pumping performance can be enhanced 2.4 times if two additional electrodes with appropriate applied voltages are added before the regular twDEP array.