Patent ID: 8637351

Claim:
A method of making devices for electrical measurements, each device comprising a plurality of micro-electrodes in the form of micro-needles protruding vertically from a substrate, the method comprising the steps of: providing a substrate having a first side and a second side opposite the first side, and electrical connections between areas on the substrate located on the first side and second side of the substrate, said connections being electrically insulated from each other by vertical insulating trenches extending through the substrate; and making said micro-electrodes in the form of micro-needles on the substrate, wherein the micro-needles are made using a silicon on insulator (SOI) wafer with a silicon layer and a buried oxide layer whereby the micro-needles are provided on the buried oxide layer of the SOI wafer, and wherein the micro-needles are made in groups on areas located on the first side of the substrate; providing electrical insulation between said areas such that the groups of micro-electrodes are electrically insulated from each other, by forming a recess in the substrate through the buried oxide layer and into the silicon layer of the SOI wafer in a region between the micro-needles and the vertical insulating trenches; placing a shadow mask over the SOI wafer such that the micro-needles and preferably only a part of the recess are exposed through the shadow mask; and applying a metal coating through the shadow mask by sputtering or evaporation such that only the micro-needles and a part of the recess are covered by a continuous layer of said metal coating.