Short characterization of miniaturized impedance sensors

Abstract

Miniaturized impedance sensors with interdigitated gold electrodes were fabricated on silicon micromechanical cantilevers. They can be used for measurement of physicochemical properties of sensor's environment. Changes of impedance spectra of sensor were examinated in selected vapor and liquid environments with various components concentration. Impedance spectroscopy was used to measure electrical response of sensor and obtain usable information from it. Experimental characteristics were approximated with electrical equivalent circuit. Model parameters for few points of humidity and NaCl concentration in solution were calculated. Study of changes of model parameters allowed to evaluate concentration changes of environment components contacting with clean and functionalized sensors surface. Functionalization of electrodes surface by suitable chemical substance may provide possibility of building a very accurate and efficient selective sensor designed to monitoring presence and concentration of selected substance in sensor's environment.