INTEGRATED COULOMETRIC SENSOR-ACTUATOR DEVICES

Bi-directional transfer of data from the chemical to the electrical do main and vice versa is possible by the integration of a coulometric ac tuator electrode with a pH-sensitive ISFET. The device thus obtained c an be operated in several modes, each offering specific advantages or new areas of application. This paper reviews the previously published applications and adds some original results. Besides a short introduct ion in the operational mechanism of the sensor-actuator device, the fo llowing applications are treated: acid or base concentration determina tion, carbon dioxide sensor, pH-static enzyme sensor, determination of diffusion coefficients, determination of buffer capacity, characteriz ation of proteins and the application of alternative electrode materia ls.