Electrophoretic Mobility

This process forms the basis for the separation in the channel, and dictates the migration velocity of a given ion in the channel. The electrophoretic mobility (pe) is related to the migration velocity (v) by eqn [1], where E is the electric field strength:

Figure 1 The fabrication process for a separation chip fabricated from silica. The first step is to place the mask on top of the silica base plate covered in deposited metal and photoresist (step 1). After this has been exposed to UV light, the chip is developed to remove the exposed photoresist and metal. It is then etched, e.g. with hydrofluoric/nitric acids (step 2); etching does not occur where the metal and photoresist remains. The final stage (step 3) is the bonding of the cover plate on to the base plate. The two etched channels can clearly be seen.

primarily since it allows the use of a wide range of new materials, and the prospect of mass production. It requires a template to be constructed, often by wet etching or mechanical milling. This template can be considered as the negative image of the channels, and is often finally produced in a more durable material, such as nickel. From this robust template, it is pos v = PeE

The units of pe, v and E are cm2 V and Vcm"1 respectively. The electrophoretic mobility is proportional to the ionic charge and frictional forces. Thus, if two mobile species differ in either their charge or the frictional forces, then separation will occur. Since uncharged molecules have an electro-phoretic mobility of zero, movement will not occur; this is why electrophoresis cannot separate neutral molecules. For ions of the same size, pe will be greater for ions with greater charge while for ions of the same charge, pe will be greater for smaller ions.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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