Simultaneous readout of multiple microcantilever arrays with phase-shifting interferometric microscopy

A complete system for the simultaneous monitoring of multiple cantilever sensors from different sensor arrays has been developed and tested for gas- and liquid-phase applications. The cantilever sensors are operated in static-deflection mode and the readout is achieved with phase-shifting interferometric microscopy (PSIM). In contrast to existing cantilever-sensor readout methods, PSIM is not dependent on alignment and allows the monitoring of the entire displacement profiles of all cantilevers within the field of view, using just one light source. To complement the PSIM readout, we have developed a sample cell, which can hold multiple cantilever-array chips, allows for very fast and reproducible sensor-chip replacement, has very low sample-volume requirements, and allows for individual or common addressing of all chips in the sample cell. We demonstrate the functionality of our microcantilever sensor system with a setup that can monitor eight cantilevers from four different sensor chips simultaneously. (C) 2009 American Institute of Physics. [doi:10.1063/1.3212667]