Abstract: An oscillation apparatus comprising: a frame; a first proof mass coupled to the frame via a spring; a driving circuit operatively coupled to the first proof mass and the frame, wherein the driving circuit is configured to induce oscillatory motion of the first proof mass relative to the frame at a resonant frequency in a first direction; a first electron-tunneling position switch operatively coupled to the first proof mass such that the first position switch is configured to pass through a closed state during each oscillation of the proof mass, wherein the position switch comprises first and second single-atom-thick tunneling electrodes; and a sensing circuit coupled to the position switch, the sensing circuit configured to output a signal whenever the position switch passes through the closed state.

Abstract: A method for adjusting the accuracy of a time-domain inertial sensor comprising the following steps: operatively positioning a harmonic oscillator of the time-domain inertial sensor between two capacitive plates; initiating harmonic oscillation of the oscillator in a first plane by creating with the capacitive plates a capacitively forced pulse; monitoring the harmonic oscillation of the oscillator; and electrostatically biasing both of the two capacitive plates such that a spring constant of the oscillator is effectively altered.

Abstract: A resonator comprising: a frame; a first oscillator configured to oscillate with respect to the frame; a first driver configured to drive the first oscillator at the first oscillator's resonant frequency; a first half of a first relative position switch mounted to the first oscillator; a second oscillator having substantially the same resonant frequency as the first oscillator, wherein the first and second oscillators are designed to respond in substantially the same manner to external perturbations to the frame; a second half of the first relative position switch mounted to the second oscillator; and wherein as the first oscillator oscillates there is relative motion between the first and second oscillators such that the first relative position switch passes through a closed state in each oscillation when the first and second switch halves pass by each other.

Abstract: An oscillatory apparatus and methods of utilizing the same. In one embodiment, the apparatus comprises a force sensor having a proof mass, with one or more sensing electron tunneling electrodes disposed thereon, and a frame comprising one or more reference electron tunneling electrodes. Conductive plates disposed on the sensor base and capping wafers induce oscillations of the proof mass. The sensing and the reference electrode pairs are disposed in a face-to-face configuration, thus forming a digital switch characterized by one or more closed states. In the closed state, the switch generates triggering events, thereby enabling the sensing apparatus to generate a digital output indicative of the mass position. The time period between consecutive trigger events is used to obtain mass deflection due to external forcing. Time separation between the triggering events is based on the physical dimensions established during fabrication, thus not requiring ongoing sensor calibration.

Abstract: A method for fabricating a monolithic micro-generator comprising: fabricating a plurality of magnet layer elements by preparing a semiconductor substrate surface to define: a plurality of coil layer recesses, a plurality of magnet wells, a plurality of integral compliant regions, and a plurality of bonding posts; disposing a ferromagnetic mass within each of a plurality of the magnet wells; fabricating a coil layer element by preparing a second semiconductor substrate surface to define a coil well, and one or more through holes, each hole disposed to accept a bonding post; disposing a conductive coil within the coil well; and bonding the upper bonding post surfaces of a magnet layer element to the corresponding upper bonding post surfaces of another magnet layer element with a coil layer element disposed between their upper surfaces such that each of the bonding posts passes through a corresponding through hole in the coil layer element.

Abstract: A method includes passing a portion of an optical signal through an aperture of a sensor having a sensing element, wherein the portion of the optical signal that passes through the aperture is an inner portion of the optical signal and the portion of the optical signal that does not pass through the aperture is an outer portion of the optical signal; producing a sensed signal by sensing the outer portion of the optical signal with the sensing element; and controlling the source of the optical signal using the sensed signal. A system for implementing the method includes an optical energy source and a sensor having an optical sensing portion and an aperture therein. The system may also include an optical isolator, a detection element, and a controller for controlling the optical energy source. The system may be used within a MEMS-based system.

Abstract: A system includes a first Fabry-Perot interferometry channel and a second Fabry-Perot interferometry channel serially and optically coupled to the first Fabry-Perot interferometry channel. One channel of the first and second Fabry-Perot interferometry channels has a greater tuning range than the other channel of the first and second Fabry-Perot interferometry channels. The Fabry-Perot interferometry channel having the lesser tuning range has a greater tuning precision than the Fabry-Perot interferometry channel having the greater tuning range. The system may be included in a MEMS-based system, such as a MEMS spectrometer.

Abstract: A method for fabricating a dual-suspension system for MEMS-based devices includes: etching the geometry of an upper spring system, a lower spring system, and a proof mass into a substrate; applying a protective barrier to cover at least the exposed portions of the first layer of silicon; etching through portions of the protective barrier and handle wafer to define the shapes of the upper spring system, lower spring system, and proof mass; removing the remainder of the protective barrier; and removing the first layer of oxide from the areas in contact with the upper spring system and removing the second layer of oxide from the areas in contact with the lower spring system. Electrical contacts may be created on the substrate. A wafer may be bonded to the support structure on a side of the substrate. A MEMS-based device fabricated from the method is also provided.

Abstract: A vibrational energy harvesting apparatus comprising: a substrate having a plurality of integral compliant regions; at least two ferromagnetic masses each coupled to a corresponding one or more of the integral compliant regions such that at least one of the ferromagnetic masses moves with respect to the substrate responsive to substrate acceleration, each ferromagnetic mass having an inner magnetic pole disposed such that the inner magnetic poles are separated by a gap, wherein the magnetic polarities of the inner magnetic poles on the opposing sides of the gap are similar; wherein the inner magnetic poles form a steep flux gradient region in and around the gap; and a coil coupled to the substrate and disposed within the steep flux gradient region where it is exposed to a changing magnetic flux arising from motion of at least one of the ferromagnetic masses with respect to the substrate.

Abstract: A vibrational energy harvesting apparatus comprising: a substrate having a plurality of integral compliant regions; at least two ferromagnetic masses each coupled to a corresponding one or more of the integral compliant regions such that at least one of the ferromagnetic masses moves with respect to the substrate responsive to substrate acceleration, each ferromagnetic mass having an inner magnetic pole disposed such that the inner magnetic poles are separated by a gap, wherein the magnetic polarities of the inner magnetic poles on the opposing sides of the gap are similar; wherein the inner magnetic poles form a steep flux gradient region in and around the gap; and a coil coupled to the substrate and disposed within the steep flux gradient region where it is exposed to a changing magnetic flux arising from motion of at least one of the ferromagnetic masses with respect to the substrate.

Abstract: A micro-electro-mechanical system (MEMS) power generator employing a plurality of magnetic masses disposed to oscillate on spring elements in a manner that produces an unusually steep flux gradient at one or more conductive coils, thereby harvesting a substantial portion of the available mechanical energy. The energy from ambient mechanical vibration is harvested to produce electrical power sufficient to power individual electronic elements for a variety of low-cost and high-performance distributed sensor systems for medical, automotive, manufacturing, robotics, and household applications.

Abstract: A Fabry-Perot cavity has a pair of partially transmissive, partially reflective, surfaces. A first of the surfaces is flexibly suspended adjacent and parallel to a second of the surfaces. A gap exists between the surfaces. A variable electrostatic potential permits this gap to be adjusted. A translucent chemical layer is disposed on the first surface. A photosensor is attached to the second surface. Light irradiates the photosensor through the chemical layer and the first and second surfaces wherein the light is also partially reflected between the surfaces. A sensing environment is provided wherein an agent undergoes a reaction with the chemical layer as well as an environment wherein the reaction does not occur. The output of the photosensor is measured to assess a change in spectrum and spectral intensity for each of the sensing environments. The gap between the surfaces as well as the light used are selected to provide an optimum photosensor output.

Abstract: A sensing system includes a ring oscillator that emits electromagnetic radiation at a characteristic frequency. The ring oscillator comprises an odd number plurality of inverters that are electrically connected in series. The sensing system also comprises a temperature stabilized voltage source that is used to supply voltage to the inverters of the ring oscillator. A sensing load for sensing a change in a preselected environmental condition is operably connected to the ring oscillator. When the load senses the preselected environmental condition, the sensing load alters the characteristic frequency of the ring oscillator and hence the electromagnetic radiation as emitted by the ring oscillator. A pick-up antenna receives the electromagnetic radiation as emitted by the ring oscillator and detection electronics, operably coupled to the pick-up antenna, measure the frequency of the electromagnetic radiation as received by the pick-up antenna.

Abstract: An accelerometer is based upon the monolithic integration of a Fabry-Perot interferometer and a p+n silicon photosensor. Transmission of light through a Fabry-Perot interferometer cavity is exponentially sensitive to small displacements in a movable mirror due to an applied accelerating force. The photosensor converts this displacement into an electrical signal as well as provides for additional amplification. Because the interferometer and photosensor are monolithically integrated on a silicon substrate, the combination is compact and has minimal parasitic elements, thereby reducing the accelerometer's noise level and increasing its signal-to-noise ratio (SNR).

Abstract: An accelerometer is based upon the monolithic integration of a Fabry-Perot interferometer and a p+n silicon photosensor. Transmission of light through a Fabry-Perot etalon is exponentially sensitive to small displacements in a movable mirror due to an applied accelerating force. The photosensor converts this displacement into an electrical signal as well as provides for additional amplification. Because the interferometer and photosensor are monolithically integrated on a silicon substrate, the combination is compact and has minimal parasitic elements, thereby reducing the accelerometer's noise level and increasing its signal-to-noise ratio (SNR).

Abstract: An improvement to an optical accelerometer based upon the monolithic integration of a Fabry-Perot interferometer and a p+n silicon photosensor includes using one or more pairs of optical accelerometers wherein each pair provides for greater accelerometer sensitivity than a single independent accelerometer, and allows for a reduction in common mode noise due to amplitude and phase difference variations of the utilized light source as well as supply voltage. The differential approach of the invention provides for the biasing of the optical accelerometers such that their output signals are 180 degrees out of phase with each other.

Abstract: A gyroscope is based upon the integration of an optical resonant cavity and a photodiode to detect minute perturbations due to angular forces. A Fabry-Perot cavity is created from two parallel semitransparent mirrors used in conjunction with a monochromatic light source. One mirror is fixed while the other is allowed to rotate with respect to the first mirror. A resonant cavity is thereby formed on either side of the axis. The gap between the mirrors is set so that light transmission through the mirrors is optimized. Rotation of the mirror from this position causes the distance between the mirrors to be altered and the light transmission on either side of the rotational axis to be change. Photodiodes on these sides sense this change as a change in photo-generated current, enabling the amount of change in rotation to be calculated. The photo-currents can be differentially amplified for sensitivity.