Piezoresistive Microcantilever for Gravimetric Particulate Matter Monitoring

A low-mass (nanogram) gravimetric direct-reading cantilever sensor is described for high-resolution portable airborne particulate matter detection and size classification. Owing to the small cantilever size, the piezoresistors for mass-induced sensing resonance-frequency shifts are connected to the cantilever as lateral struts. The cantilever is arranged over a microchannel through which particle-laden air is conducted. For size-selective deposition of charged particles on the cantilever an electrostatic field is applied between it and the microchannel wall. Realised sensors are tested against a standard particle sizer instrument in a chamber with carbon nanoparticles of mass concentrations of ???10 myg/m??.