Study on AC Electro-osmosis Driving Aqueous Solution

Microfluidic drive and control are vital technologies, used in the microfluidic chip. The AC electro-osmotic drive has the advantages of using low voltage, hard to generate any bubbles, and electrodes can be easily dressed onto the chip. Therefore, it has profound economic value and scientific significance in micro-electromechanical systems. In this experiment, study on the AC electro-osmotic asymmetric electrode micro-pump drives aqueous solutions are conducted. The AC electro-osmotic flow of three aqueous solutions; potassium hydroxide (KOH), potassium acetate (CH3COOK), and potassium chloride (KCl) were tested. The experimental results showed that the AC electro-osmotic flow rate of KOH solution and CH3COOK solution were relatively small. When both solutions were under the high frequency of AC electrical signal, the direction of flow will be changed. Only the KCl solution flowed more steadily and at the greatest speed. With the increase of the conductivity of the solution, the electro-osmotic microflow rate of the KCl solution increased first and then droped. The electro-osmotic microflow rate had reached the highest when the KCl solution conductivity was 10 μs/cm. Therefore, we conclude that increasing the voltage will significantly increase the AC electro-osmotic microflow rate.