Nano-resonator inertial sensor assembly
View Patent ↗The invention is a frequency modulated (FM) inertial sensing device and method which, in one embodiment, comprises an accelerometer having a proof mass coupled to a nano-resonator element. The nano-resonator element is oscillated at a first predetermined frequency, which may be a first resonant frequency, and is altered to oscillate at a second frequency, which may be a second resonant frequency, in response to a resultant force produced by the acceleration of the proof mass. The degree of change in nano-resonator element output frequency is sensed and processed using suitable processing circuitry as a change in acceleration.
1. An inertial sensor comprising:
a proof mass suspended on a centrally-disposed anchor by a plurality of micro-beams that are longitudinally disposed orthogonal to a direction of deflection of the sensor,
the proof mass coupled to a plurality of nano-resonators that are longitudinally disposed orthogonal to the direction of deflection,
the nano-resonators comprising a sense means and a drive means disposed on a first thickness of the nano-resonators,
the nano-resonators configured to be capable of being oscillated at a first predetermined frequency and configured to be capable of being altered to oscillate at a second frequency in response to a resultant force produced by an inertia of the proof mass.
2. An inertial sensor comprising:
a centrally-disposed anchor coupled to a substrate,
a proof mass having a second thickness coupled to the anchor and suspended over the substrate by means of at least one micro-beam that is longitudinally disposed orthogonal to a direction of deflection of the sensor,
a plurality of nano-resonators each having a first thickness,
the plurality of nano-resonators coupled to the anchor and to the proof mass,
the nano-resonators longitudinally disposed orthogonal to the direction of deflection,
nano-resonator drive means for driving the nano-resonators at a first predetermined frequency, and,
sensing means for detecting nano-resonator output frequency.
3. The inertial sensor of claim 2 wherein the second thickness is at least about ten times greater than the first thickness.
4. The inertial sensor of claim 2 wherein the second thickness is greater than about 100 microns and the first thickness is less than about one micron.
5. The inertial sensor of claim 2 wherein the sensor further comprises proof mass drive means for oscillating the proof mass at a proof mass frequency,
the proof mass and the nano-resonator element coupled whereby the proof mass frequency modulates the nano-resonator output frequency.
6. A method for sensing acceleration comprising the steps of:
providing a proof mass suspended on a centrally-disposed anchor by a plurality of micro-beams that are longitudinally disposed orthogonal to a direction of deflection of a sensor,
the proof mass coupled to it plurality of nano-resonators that are longitudinally disposed to the direction of deflection,
the nano-resonators comprising a sense means and a drive means,
oscillating the nano-resonator at a first predetermined frequency,
detecting the output frequency of the nano-resonators in response to an acceleration of the proof mass, and,
measuring a rate of acceleration based on a shift in frequency from the first predetermined frequency to the output frequency.