Furthermore the apparatus
1 demonstrates successful formation of a layer
11 across the recess
5 of each diameter in the range of 5 μm to 100 μm. Accordingly the apparatus
1 was used to investigate the role of the diameter of the recess
5 and the quantity of pre-treatment coating applied, by experimentally testing the percentage success rate of forming a layer
5 with three different concentrations of pre-treatment coating
30, namely 0.5%, 1.0%, and 2.0% hexadecane in pentane. The results showed that in the case of too little pretreatment coating
30, it was not possible to form the layer
11 across the range of diameters of recess
5. Furthermore in the case of too much pretreatment coating
30, it was not possible to wet the electrode
21 and formation of the layer
11 could not be observed. In this particular configuration, the yield of formation of layers
11 was greater than 60% for the range of diameters 15 μm to 100 μm. Factors affecting layer formation, some of which were investigated in this experiment include, but are not limited to, pretreatment coating
30, diameter of recess
5, depth of recess
5, aspect ratio of recess
5, surface properties of the recess
5, surface properties of the surfaces around the recess, fluid flow within the chamber
7, the amphiphilic molecules used in the layer formation and the physical and electrical properties of the electrode
21 within the recess
5. Subsequent experiments have demonstrated yield of formation of layers
11, verified by stochastic binding signals of inserted membrane channels, greater than 70% using the 128 recesses, each 100 μm in diameter, of the device of
FIG. 28.