Abstract: A combinatorial chemical formation and assay disc (1) having a base (20) and an upper surface (26) and a lower surface, one of the upper or lower surfaces being an assay surface and a data surface (40) spaced from the assay surface wherein the data surface is on or within the assay disc. The assay surface has a conductive layer (64) on the base, a dielectric or photo-conductive layer (66) on the conductive layer and a chemically functional layer (68, 69) on the dielectric or photo-conductive layer. The assay surface may be planar or include three dimensional features (100, 168).

Abstract: A combinatorial chemical formation and assay disc (1) having a base (20) and an upper surface (26) and a lower surface, one of the upper or lower surfaces being an assay surface and a data surface (40) spaced from the assay surface wherein the data surface is on or within the assay disc. The assay surface has a conductive layer (64) on the base, a dielectric or photo-conductive layer (66) on the conductive layer and a chemically functional layer (68, 69) on the dielectric or photo-conductive layer. The assay surface may be planar or include three dimensional features (100, 168).

Abstract: An emulsion including a continuous phase, a discontinuous phase which is immiscible in the continuous phase, and optionally a surfactant, the surfactant has a first part which is compatible with the continuous phase and a second part which is compatible with the discontinuous phase. The continuous phase has a high volume resistivity and the discontinuous phase is electrically charged. The discontinuous phase can be a reagent, a solvent which carries an active chemical reagent or a carrier liquid for a solid or insoluble liquid dispersed in the discontinuous phase. The surfactant, if present, is selected to not significantly reduce the volume resistivity of the continuous phase. The emulsion can also include a charge control agent. The emulsions can be used for the electrostatically controlled placement of matter in a spatially defined manner from the discontinuous phase for combinatorial chemistry and micrometer and nanometer scale deposition with or without reaction.

Abstract: A method of fabrication or manufacture at micrometer and nanometer scale by spatially selective deposition of chemical substances so as to form a solid phase array on a substrate (10) which includes the steps of defining a region (15) on the substrate by forming an electrostatic charge on that region which is different from the electrostatic charge on other regions of the substrate such as by formation of a latent electrostatic image thereon, applying an emulsion to the substrate. The emulsion (16) has an electrically charged discontinuous phase and a component to be selectively deposited carried in or comprising the discontinuous phase. The discontinuous phase of the emulsion is attracted to the preselected region by attraction by the electrostatic charge on the region and deposition obtained with or without reaction. The electrostatic image may be formed by the use of photoconductor.

Abstract: A substrate (1) for spatially selective micron and nanometer scale deposition and/or reaction, which has a support (3), a conductive layer (5) on the support, a dielectric layer (7) to hold an electrostatic charge pattern such as a photoconductive layer of a material which dissipates an electric charge upon receiving incident radiation thereon, and a chemically functional layer (9), such that electrostatic charge patterns may be formed in a predetermined manner upon the substrate to influence the movement of charged droplets in an emulsion (15) on the substrate. The chemically functional layer either provides a surface for chemical functionalisation of the substrate or prevents access or reaction to the dielectric or photoconductive layer.