Development of chemically sensitive field-effect transistor arrays and selective materials

The purpose of this work was to fabricate an integrated chemical sensor array based on the field-effect transistor. The work was motivated by the need to develop a sensing platform that could be used to monitor the work function and impedance changes of a wide variety of chemically active materials. The work proceeded in two major stages. First, an array of eight field-effect transistors was microfabricated with standard silicon technology. The transistor sensor array had the advantages of small size, low power consumption, and simple integration with other silicon electronics. Second, active materials were developed which had a tunable initial work function. All the active materials were based on the semiconducting polymer, polyaniline. Material formulations included polyaniline blended with calixarenes, photoacid generators, and charge-transfer salts. The physical properties of the materials were characterized with electrochemical, spectroscopic, and work function measurements.