This thesis presents the theory and experimental results on two topics: the electroosmotic (EO) pump and the electrorheological effect in microemulsions. In the first section, I gave the theoretical background, the sample fabrication and experimental measurements of the fluid flow for the electroosmotic pump. The electroosmotic pump is basically a simple microchannel in which the channel wall exhibits the charge separation effect. The result of the experiment shows that when an electric field was applied across the microchannel, there can be fluid flow with no moving parts, i.e., the electroosmotic pump operates as a pump with no moving components. My results also show that the efficiency of the electroosmotic pump increases with decreasing channel diameter, thereby verifying the EO to be an interfacial effect.

In the second section, the electrorheological effect in water-in-oil microemulsions is presented in both its theoretical and experimental aspects. Based on the theory of the dielectric electrorheological effect and the giant electrorheological effect, a device for observing and recording data of the microemulsions was made. The experimental results show that by applying an electric field to the water-in-oil microemulsions under the constant flow rate condition, one can observe a measurable pressure difference that correlates with the applied field, i.e., the electrorheological effect. This effect is apparently caused by the rearrangement of microemulsion particles into aligned columns along the applied field direction. Also, the experimental results show that the pressure difference increases with decreasing size of the microemulsion particles.

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