Apparatus and method for ultrasensitive nanoelectromechanical mass detection
AssigneeCalifornia Institute of Technology
InventorsMichael L. Roukes, Kamil L. Ekinci
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Abstract
The invention relates to the application of the techniques of nanoelectromechanical systems (NEMS) to ultrasensitive mass detection. A pulsed flux of atoms is adsorbed onto the surface of a 32.8 MHz nanomechanical resonator within an ultrahigh vacuum environment. The mass-induced frequency shifts from these adsorbates are then used to demonstrate a mass sensitivity of ˜1.46×106 Daltons (Da). For resonators operating up to frequencies of 72 MHz, inverse mass responsivities as small as ˜8×10−20 grams/Hz (5×104 Da/Hz) are obtained. Our results offer a new approach to ultrahigh resolution mass spectrometry of individual, electrically-neutral macromolecules with clear prospects for single Dalton sensitivity.
Claims25
An apparatus for measuring microscopic magnitudes of mass comprising:
- a nanoelectromechanical resonator arranged and configured in a vacuum to receive added mass to a vibrating element included within the resonator;
- and
- an electronic circuit to drive the resonator and to measure a mechanical resonance frequency of the resonator,
- whereby changes in the frequency of oscillation of the resonator indicate the magnitude of mass added to the vibrating element.
A method for measuring microscopic magnitudes of mass comprising the steps of:
- providing a nanoelectromechanical resonator arranged and configured to receive added mass to a vibrating element included with the resonator, an electronic circuit to drive the resonator and to measure a frequency of oscillation of the resonator;
- enclosing the nanoelectromechanical resonator in a vacuum chamber;
- driving the vibrating element with the circuit to establish a steady state resonant frequency;
- adsorbing mass onto the vibrating element;
- and
- sensing the change of the steady state resonant frequency as a direct measure of the adsorbed mass,
- whereby changes in the frequency of oscillation of the resonator indicate the magnitude of mass added to the vibrating element.
Dependencies are inferred from the claim text.