Electro less deposition and structuring of silver electrodes inside closed micro fluidic channels

摘要

This paper presents a method to deposit and structure silver electrodes inside capillaries made by silicon micromachining and oxidation for applications such as dispensing and electro-chemically sensing liquids. The electrode deposition was performed after having micro fabricated the capillaries. To increase the adhesion between the metal and the SiO_2 capillary, an intermediate layer of 3-mercaptopropylmethyldimethoxysilane (3-MPS) was deposited out of the vapor phase. The used electro-less silver plating (ELSP) solution consisted of a modified Tollens' reagent. The structuring of the electrodes was achieved by stopping the ELSP solution from completely filling the capillary by means of micro fluidic stop valves.