Abstract: Micro-neuroelectrodes for use in stimulation of neurons can be formed having decreased impedance, increased charge storage capacity, and good durability. A method of coating a micro-neuroelectrode includes sputtering a film of iridium oxide on a surface of the micro-neuroelectrode. The sputtering can occur using pulse-DC conditions under reactive conditions that are sufficient to form a polycrystalline iridium oxide film that adheres to the surface of the micro-neuroelectrode. The deposited iridium oxide film can also be optionally activated to increase its charge storage capacity.

Abstract: A method of fabricating a sub-millimeter scale curved surface on a substrate (10) includes cutting a plurality of trenches (12) of varying depth into the substrate (10). The depth of the trenches (12) corresponds to a desired surface profile. The substrate (10) is etched to remove material left (16) between the trenches to form the curved surface.

Abstract: A micro-needle array having tips disposed along a non-planar surface is formed by shaping the wafer surface into a non-planar surface to define the tips of the micro-needles. A plurality of trenches are cut into the wafer to form a plurality of columns having tops corresponding to the non-planar surface. The columns are rounded and sharpened by etching to form the micro-needles.

Abstract: Methods for wafer-scale fabrication of needle arrays can include mechanically modifying a wafer to produce a plurality of vertically-extending columns. The columns are etched to round and reshape the columns into substantially uniformly shaped needles. Needle arrays having needle width non-uniformity of less than about 3% and length non-uniformity of less than about 2% can be produced.

Abstract: A method of masking high-aspect ratio structures on a wafer includes submerging the wafer in a resist material so that the high-aspect ratio structures are at least partially embedded within the resist material. The resist material is cured and further processing steps, such as for example oxygen plasma etching, are applied, for example to remove portions of the resist material and material from upper portions of the high-aspect ratio structures.