A unipolar corona discharge microfabricated ionizer structure for gases at atmospheric pressure and composition

To miniaturize airborne participates sizing and counting apparatus for ubiquitous deployment in air quality monitoring and epidemiological studies, we developed a unipolar corona discharge microfabricated ionizer structure for gases at atmospheric pressure and composition. It consumes relatively low power at 150 mW or less, and operates with either single or multiple discharge electrodes. Potential difference of several kilovolts is maintained between the discharge electrodes within a chip size of less than 1 cm/sup 2/ without substrate breakdown or undesired sparkover. Mechanical oscillation of discharge electrode due to electrohydrodynamic effects is minimized. Corona charging currents of more than 40 /spl mu/A was achieved before streamers breakdown. Laplacian field simulation for both single and dual cathode design was performed using ANSYS/spl trade/.