Time-Resolved Evaporation Rate of Attoliter Glycerine Drops Using On-Chip CMOS Mass Sensors Based on Resonant Silicon Micro Cantilevers

The time-resolved evaporation rate of small glycerine drops (in the attoliter range) is determined by means of a mass sensor based on a resonant cantilever integrated in a CMOS chip. The cantilever is fabricated on crystalline silicon, using silicon-on-insulator (SOI) substrates for the integration of the CMOS-MEMS. Glycerine drops are deposited at the free end of the cantilever. The high mass sensitivity of the sensor (8 ag/Hz) allows to determine the evaporation rate for glycerine drops smaller than 500 aL, which are found to be below 3.2 aL/s in volume or 4 fg/s in mass.