Automation and control of biological samples and solutions at microscxale is a major advantage for biochemistry analysis and biological diagnostics. Despite the known potential of miniaturization in biochemistry and biomedical applications, comparatively little is known about fluid automation and control at microscale. Here, we study the electric field effect inside a fluidic channel and proper electrode structures with different patterns propose to form forward, reversal and rotational flows inside the channel. The simulation results confirmed that the ac electro-thermal flow is efficient for control and automation of high conductive solutions. The fluid pumping and mixing effects were numerically studied by solving physic-coupled electric, temperature, hydrodynamic and concentration fields inside a microchannel. From experimental point of view, the electrode structures deposited on a silicon substrate and bonding to a PDMS microchannel, high conductive water solution is seeded with fluorescent particles and inserted inside the PDMS channel. By measuring the frequency response of the fluid and exciting the electrodes with proper voltage, the fluid motion is observed inside the channel through the CCD camera. Based on the results, there is good agreement with the experimental and simulation studies
