The bimolecular lipid membrane (BLM) is modeled as a bulk elastic layer subject to a compressive electric force caused by applied voltages. Analysis of this model shows that a compressive instability develops when the electric stress exceeds a critical value. This instability tends to crush the film and thus rupture it. The predicted breakdown voltage, when compared with measured values for phosphatidylcholine and cholesterol, shows fair agreement, considering the uncertainty in the estimate of elastic parameters.

Abstract— The Gyricon display consists of hemispherical black and white (bichromal) balls contained in individual liquid‐filled cavities and disposed to orient in an electrical field. This bistable reflective light display currently has a diffuse reflectance of more than 18% and a contrast ratio of more than 6:1. The viewing angle approaches that of paper. A new method of fabricating the bichromal balls has enabled practical realization of large‐area high‐quality displays.

When a layer of particles moves through a viscous liquid it experiences forces which tend to disrupt the layer into clusters of particles separated by open channels. A theoretical description of this process is presented and a viscous instability is predicted. The spatial growth of the instability is approximated by eγz, where \[ \gamma = {\textstyle\frac{3}{2}} a/d^2, \] where a is the particle radius and d is the average distance between particles. This result implies that any initial irregularity in a uniform particle distribution will be amplified by viscous forces alone. Significant amplification will occur when the particle has drifted a small multiple of the separation distance, if this separation is not much greater than the particle diameter. Thus, any initially uniform particle layer will form clusters as it drifts through a viscous fluid. The distance in which this clustering occurs will be unaffected by changes in the particle velocity, as long as the Reynolds number remains small. The preferred form of irregularity will consist of small clusters separated by individual particles which trail some distance behind. Experimental verification of these conclusions is presented.

Selecting a Working Fluid to Increase the Efficiency and Flow Rate of an EHD Pump Abstmcr-The ultimate flow rate and velocity of an electrohydrodynamic (EHD) pump with a given length and depth are determined by the material properties of the working fluid. High dielectric constant and low viscosity lead to high flow velocities, while low conductivity and mobility promote high efficiency. A fundamental model of EHD pumping is formulated to account for the material properties of the working fluid, and is applied to several experimental pumps reported earlier, with generally good agreement. An example of the use of this model to select a working fluid for a typical pump suggests several new liquids suitable for EHD pumping.

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