Thick film 3-D electrode configuration for electrochemical applications

Miniature electrochemical sensors can be economically produced by thick-film technology. An area of working electrode and an electrode topology design is the important parts of design optimization of electrode system. The design of standard thick-film electrode construction is limited (2-D construction, substrate dimensions, resolution, paste parameters …). Therefore rules for classical electrode systems cannot be used fully in this case and larger electrode area can be making by 3-D structure only. One of resolutions is unconventional method. The increase of electrode surface by unconventional method — ball and wire bonding is discussed in this paper. The sensors with standard TFT gold surface of working electrode and increased surface of working electrode, e.q. by gold bonds and gold wires, was tested and compared. The practical measurement was made in a model reversible system, alkaline solution mixture of potassium ferricyanide and potassium ferrocyanide, and in solution with heavy metals. The first results show that the thick-film electrochemical sensors with standard gold surface of working electrode have lowest output current signal than sensors with new electrode configuration. The new designed sensor with modified surface by gold wires shows is one of the best results by all types of measured sensors.