The potential ability of micromechanical/nanomechanical silicon resonators with thicknesses of 500 and 146 nm to detect mass and charge in an ion attachment is investigated in vacuum. Low-energy ions are generated by an ionizer and filtered by a quadrupole mass filter. The vibration of the resonator is measured using a laser Doppler vibrometer, which self-oscillates at its fundamental resonant frequency by feedback-controlled electrostatic actuation. The vibration amplitude is kept at a constant with the auto gain control of the feedback loop. The attachment of ions on the one side of the resonator induces the surface stress, resulting in the change of the resonant frequency. Also the feedback gain that keeps the amplitude at a constant changes due to the charge deposition. The measurement of the mass-induced stress of 9.7× 10-7 Nm that resulted from a mass attachment smaller than 69 Zg is demonstrated using the 146-nm-thick silicon resonator.
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