Abstract

Fabrication and electrical characterization of micro-gaps and their properties are discussed with their applications in electrochemical sensors and bimolecular detection. To understand the relationship between the biosensor and micro-structure we have carried out the fabrication and characterization of micro-gap structures for yeast concentration measurement. In this paper two photo mask designs are used. The first mask is for defining the lateral micro-gap and the second one is for the aluminum electrode pattern. Lateral micro-gaps are formed using polysilicon and Al as contact pads. Conventional photolithography techniques are used to fabricate the micro-gap. The electrical measurements were carried out using a Semiconductor Parameter Analyzer to measure the change in capacitance across the micro-gap with the yeast solution drop put across the gap. The measured value of capacitance for each yeast concentration is presented as a function of the gap size. The results indicate that these micro-gaps could possibly be used for yeast sensor applications.

Key words: Micro-gap, conductivity, yeast detection, capacity, electrochemical sensor.