Chemically Modified Microelectrode Arrays: New Kinds of Electronic Devices

Modification of closely spaced (~1.5 pm) microelectrodes (~2.5 pm wide x 50 pm long x 0.1 pm high) with electroactive materials gives rise to a variety of new kinds of "electronic devices". Surface modification of microelectrode arrays with metal oxides, e.g. W03, conventional redox polymers, e.g. viologen-based polymers, and so-called conducting redox polymers, e.g. poly(3-methylthiophene), allows demonstration of a variety of microelectrochemical "transistors" having properties that depend on the electroactive material. While the response time of such devices is slow by solid state electronics standards, chemically sensitive transistors can be envisioned as sensitive, specific sensors. Solid state microelectrochemical devices can be made that involve the use of ionic conducting polymers as the "solvent"/ electrolyte system. Solid state microelectrochemical transistors can be designed to be sensitive to certain gases.