Attoscale Mass Detection
Sensing of small mass changes
The “heart” of the measurement system is the functionalized resonator (cantilever-sensor). In principle, this sensor is a mechanical oscillator with a defined resonant frequency. The surface of this sensor is prepared to be attractive to certain kinds of substances. Sticking to the sensor surface, those substances amend the mass and the resonant frequency of the sensor.
The exceptionally low effective mass of those resonators allows them to reach very high mass resolutions of the order of only a few ag (10-18g). By detecting the resonance frequency shift (or phase shift), it is possible to discover ultimately low mass changes. The very accurate measurement of the frequency shift allows calibrating in situ Electron Beam Induced Deposition (Etching) processes, identifying diseases using label-free biomarkers, or recognizing hazards and pollutions.