Abstract: This application relates to an apparatus and system for sensing strain on a portion of an implant positioned in a living being. In one aspect, the apparatus has at least one sensor assembly that can be mountable thereon a portion of the implant and that has a passive electrical resonant circuit that can be configured to be selectively electromagnetically coupled to an ex-vivo source of RF energy. Each sensor assembly, in response to the electromagnetic coupling, can be configured to generate an output signal characterized by a frequency that is dependent upon urged movement of a portion of the passive electrical resonant circuit and is indicative of strain applied thereon a portion of the respective sensor assembly.

Abstract: The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency or set of frequencies and a predetermined amplitude. The energizing signal is coupled to the sensor via magnetic coupling and induces a current in the sensor which oscillates at the resonant frequency of the sensor. The system receives the ring down response of the sensor via magnetic coupling and determines the resonant frequency of the sensor, which is used to calculate the measured physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal.

Abstract: A position detecting device includes: a position indicator operable to resonate at a first frequency, upon receipt of an excitation signal, to oscillate at a second frequency different from the first frequency so as to generate an oscillation signal, and to transmit the oscillation signal thus generated; and a position detector operable to generate the excitation signal and to transmit the excitation signal to the position indicator, and configured to perform band pass filtering and amplitude detection upon the oscillation signal received thereby for generating a processed signal, and to obtain information corresponding to position of the position indicator relative to the position detector based on the processed signal. A frequency range of the band pass filtering includes the second frequency and excludes the first frequency.

Abstract: A device for sensing a chemical analyte is disclosed. The device is comprised of a vibrating structure having first and second surfaces and having an associated resonant frequency and a wire coupled between the first and second surfaces of the vibrating structure, wherein the analyte interacts with the wire and causes a change in the resonant frequency of the vibrating structure. The vibrating structure can include a tuning fork. The vibrating structure can be comprised of quartz. The wire can be comprised of polymer. A plurality of vibrating structures are arranged in an array to increase confidence by promoting a redundancy of measurement or to detect a plurality of chemical analytes. A method of making a device for sensing a chemical analyte is also disclosed.

Abstract: A sensor system includes a first sensor, a second sensor, and an analyzer circuit, the first sensor including a first seismic mass having a first resonance frequency and the second sensor including a second seismic mass having a second resonance frequency, and the analyzer circuit being provided for analyzing a first output signal of the first sensor as well as a second output signal of the second sensor and, moreover, the first resonance frequency being unequal to the second resonance frequency.

Abstract: A method for sensing physical, chemical, and biological characteristics of an environment is provided. The method comprises using a radio frequency identification (RFID) sensor component having a predetermined range of power initiation levels and having predetermined resonant circuit parameters comprising the steps of activating the RFID sensor component and determining whether a range of power levels, needed for activating the sensor component, is below the predetermined range of power initiation levels; sensing at least one of the physical, chemical, and biological characteristics of the environment; quantifying the sensed characteristic of the environment using one or more selected resonant parameters, wherein the selection of parameters is based in part on the range of power levels needed to activate the sensor.

Abstract: A capacitive proximity sensor giving a long front detection range with less erroneous detection. A capacitive proximity sensor detects an approach of an object such as a human body or so by its capacitance change. The capacitance in a capacity composed by a first electrode and a second electrode in the sensor varies according to the approach of the object in distance. The first electrode (1) is in a linear shape at a small surface area such as an electric wire. The second electrode (2) is in a planar shape at a large surface area such as a flat plate or a sheet. The first electrode (1) and the second electrode (2) are arranged in parallel at a separation. A front detection region in front of the capacitive proximity sensor is at a side where the first electrode (1) appears upon the second electrode (2). A shield electrode (8) is placed behind the second electrode (2) face to face in parallel at a separation. The shield electrode (8) is grounded.

Abstract: MEMS in-plane resonators include a substrate wafer, at least one resonant mass supported by the substrate wafer and configured to resonate substantially in-plane, and at least one transducer coupled to the at least one resonant mass for at least one of driving and sensing in-plane movement of the at least one resonant mass, wherein at least part of one surface of the resonant mass is configured for exposure to an external environment and wherein the at least one transducer is isolated from the external environment. Such MEMS in-plane resonators may be fabricated using conventional surface micromachining techniques and high-volume wafer fabrication processes and may be configured for liquid applications (e.g., viscometry, densitometry, chemical/biological sensing), gas sensing (e.g., where a polymer film is added to the sensor surface, further degrading the damping performance), or other applications.

Abstract: An electromagnetic induction coordinate detecting method for detecting the trace of at least one electromagnetic pointing device on an electromagnetic sensor board is disclosed. The method includes the following steps: first, a delayed period for each electromagnetic pointing device is pre-determined. Then, whether a board-trigger signal from the electromagnetic sensor board is received is determined. If yes, the electromagnetic pointing device emits an electromagnetic signal after the delayed period. Finally, the electromagnetic sensor board calculates the coordinate and the pressure of each electromagnetic pointing device according to the received electromagnetic signal.

Abstract: Systems and methods for estimating a physical characteristic of a seafood product are provided. In one system, the estimate is based on a slope defined by a ratio of changes in peak resonant amplitude and frequency of an electromagnetic resonant circuit in loaded and unloaded states. In another system, a first probe of a plurality of probes is driven with a test signal when the plurality of probes is loaded by a seafood product and the estimate is based on received test signals at one or more of the other probes. In another system, the estimate is based on the loading effect of a seafood product on an electromagnetic resonant circuit, which is also used to read an ID from an RFID associated with the seafood product. The systems and methods may be used for individual specimens, or to determine an average estimate for multiple specimens at one time.

Abstract: A resonance scanning system and method for testing equipment for electromagnetic resonances uses a resonance detection subsystem with at least one probe to identify at least one of a resonating location, a resonating frequency and a quality factor of a resonance of the equipment and an automatic scanning subsystem to displace the probe to different testing locations of the equipment so that the resonance detection subsystem can determine if any of the different testing locations of the equipment exhibits electromagnetic resonances.

Abstract: A resonance power transfer system and a method for tracking resonant impedance in the resonance power transfer system are provided. An apparatus for tracking resonant impedance in a resonance power transfer system may include: a load sensor configured to detect the impedance of a load connected to a target device that receives resonance power; a target reflection signal detector configured to detect a reflection signal corresponding to the resonance power; a target impedance tracking unit configured to track the resonant impedance by adjusting a determination factor of a resonant frequency; and a target control unit configured to control the tracking of the resonant impedance based on whether there is a change of the impedance of the load, the reflection signal is detected, or both.

Abstract: A non-destructive on-line system for detecting a presence of a material in a sample of a substance, including: an MRI device; a flow conduit encompassed by the tunable RF coil of the MRI device and having an input duct and an output duct; a flow of the sample through the flow conduit; a signal detector for detecting frequency-dependent output signals from the MRI device as a function of a frequency variation of the RF tunable coil within a frequency range of an RF resonant frequency of a standard sample of the substance, and a processing unit.

Abstract: A piezoelectric sensor having a plurality of electrodes deposited on a single surface of the dielectric medium is generally provided. The plurality of electrodes can define a plurality of square-shaped electrodes forming a grid on the first surface of the dielectric medium while the second electrode defines a continuous electrode. An electrode border surrounding the plurality of electrodes can be deposited on the first surface of the dielectric medium. Alternatively, the plurality of electrodes can define column-shaped electrodes, while the second electrode defines a plurality of row-shaped electrodes separated by etchings. The direction of orientation of each column-shaped electrode and the direction of orientation of each row-shaped electrode can be substantially perpendicular. A method of making a piezoelectric sensor is also provided.

Abstract: Disclosed is an apparatus for estimating a property of a fluid. The apparatus includes: a piezoelectric resonator configured to be disposed in the fluid; an electrode embedded in the piezoelectric resonator and included in a resonator circuit configured to output an electrical signal related to the property; a discontinuity defined by a surface of the piezoelectric resonator, the discontinuity altering an impedance of the resonator circuit if a high-dielectric fluid or a conductive fluid is disposed in the discontinuity; and an insulating material disposed in the discontinuity.

Abstract: This invention relates to a method and system for remote detection of a targeted substance by the appropriate application of a probing signal that induces molecular resonance in the target substance to create an identifiable signature or response. In the preferred embodiment, signals transmitted are an Infrared laser beam, amplitude modulated in the range of 100 kHz frequency. The probing signal stimulates molecular resonance of the target substance which produces characteristic electron signal responses that are detected by IR detectors. A software program is used to process the electrical response signals and to compare them with electrical response signals stored in a database of known substances, thus allowing the target substance to be identified. The system may also be used to locate targeted substances. Also disclosed is an artificial ground device that provides a positive ground that provides consistent responses.

Abstract: The invention relates to MEMS resonators. In one embodiment, an integrated resonator and sensor device includes a micro-electromechanical system (MEMS) resonator, and an anchor portion coupled to the MEMS resonator and configured to allow resonance of the MEMS resonator in a first plane of motion and movement of the MEMS resonator in a second plane of motion. In other embodiments, additional apparatuses, devices, systems and methods are disclosed.

Abstract: A detection element for detecting an electromagnetic wave includes: a substrate; a schottky barrier diode disposed on the substrate; and an antenna disposed on the substrate, wherein the antenna includes a first conductive element and a second conductive element which are divided, a third conductive element and a fourth conductive element which are divided, a first connecting member that electrically connects the first conductive element and the third conductive element, and a second connecting member that electrically connects the second conductive element and the fourth conductive element, wherein the first conductive element and the second conductive element, and the third conductive element and the fourth conductive element are formed on multiple surfaces of the substrate, which are spaced apart from each other along an incident direction of the electromagnetic wave, respectively, and wherein the schottky barrier diode is electrically connected between the first conductive element and the second conductiv

Abstract: A sensor assembly for electric field sensing is provided. The sensor assembly may include an array of Micro-Electro-Mechanical System (MEMS)-based resonant tunneling devices. A resonant tunneling device may be configured to generate a resonant tunneling signal in response to the electric field. The resonant tunneling device may include at least one electron state definer responsive to changes in at least one respective controllable characteristic of the electron state definer. The changes in the controllable characteristic are configured to affect the tunneling signal. An excitation device may be coupled to the resonant tunneling device to effect at least one of the changes in the controllable characteristic affecting the tunneling signal. A controller may be coupled to the resonant tunneling device and the excitation device to control the changes of the controllable characteristic in accordance with an automated control strategy configured to reduce an effect of noise on a measurement of the electric field.

Abstract: A system and apparatus for providing an in-vivo assessment of relative movement of an implant that is positioned in a living being is provided that includes a first assembly and a second assembly that are positioned within the living being. The first assembly includes a passive electrical resonant circuit that is configured to be selectively electromagnetically coupled to an ex-vivo source of RF energy and, in response to the electromagnetic coupling, generates an output signal characterized by a frequency that is dependent upon a distance between the first assembly and the second assembly at the time of the electromagnetic coupling.

Abstract: There is provided to a method for measuring antenna characteristics operating in an out-of-operational frequency range of a chamber, in the chamber having a predetermined operational frequency range, including the steps of: a) measuring reflected wave characteristics of the out-of-operational frequency range generated within the chamber; b) measuring the characteristics of a measurement target antenna operating in the out-of-operational frequency range of the chamber; and c) measuring final characteristics of the measurement target antenna by compensating the characteristic data of the measurement target antenna measured in the step b) for reflected wave data measured in the step a).

Abstract: The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency or set of frequencies and a predetermined amplitude. The energizing signal is coupled to the sensor via magnetic coupling and induces a current in the sensor which oscillates at the resonant frequency of the sensor. The system receives the ring down response of the sensor via magnetic coupling and determines the resonant frequency of the sensor, which is used to calculate the measured physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal.

Abstract: A generator generates radio-frequency electromagnetic radiation to a resonator whose resonance frequency is affected by a characteristic to be measured of an object to be measured. A receiver receives radio-frequency electromagnetic radiation from the resonator and a signal processing unit searches for a resonance frequency of the resonator for measuring the characteristic to be measured. The generator comprises a digital frequency synthesizer for scanning a frequency of radio-frequency electromagnetic radiation to be applied to the resonator over a desired frequency band by using discrete measuring frequencies.

Abstract: The invention relates to a device for touch/proximity detection, especially a capacitive switch device, which is designed to set switching states by approaching the switch device or by touching the switch device, in order to perform, for example, switching actions on an instrument. The invention also relates to a switch device, especially a switch device on a capacitive basis, for a cooktop, for operating the cooktop.

Abstract: A coupling loop or antenna is provided that can be used with a system that determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. In one embodiment orientation features are provided for positioning the coupling loop relative to the sensor to maximize the coupling between the sensor and the coupling loop.

Abstract: An occupant detection system that includes an electrode, an electrical network, and a controller. The electrode is arranged to be proximate to an expected location of an occupant for sensing an occupant presence proximate the location. The electrode is configured to provide an electrode impedance indicative of the occupant presence. The electrical network is coupled to the electrode to form a resonant circuit and is configured to provide a network impedance. The resonant circuit is configured to exhibit a resonant frequency dependent on the network impedance and the electrode impedance. The controller is coupled to the resonant circuit and is configured to determine the resonant frequency and detect an occupant based on the resonant frequency.

Abstract: A radio wave intensity measuring device includes a radio wave absorber (100) configured to include a plane having a plurality of cells (CL11, CL12, . . . ) and to absorb a radio wave entering the plane, and a measurer (200) configured to measure radio wave intensities in a plurality of cells.

Abstract: A plurality of through-hole vias connected to conductor layers is disposed with gaps left between these vias around opening parts disposed in the conductor layers in a printed board in which these conductor layers are disposed parallel to each other so as to sandwich a dielectric layer in between. Furthermore, through-hole vias used for excitation are disposed in the opening parts of the conductor layers and regions of the dielectric layer matching these opening parts in a non-contact manner with the conductor layers. When the complex dielectric constant is measured, a high-frequency power is applied to the through-hole vias, and the power loss between the through-hole vias and the conductor layers is measured by the S parameter method.

Abstract: A wireless sensor having a primary passive electrical resonant circuit that has an intrinsic electrical property that is variable in response to a characteristic of a patient and a secondary passive electrical resonant circuit. In one aspect, the primary passive resonant circuit can be positioned into a tuned position in response to the actuation of the secondary passive electrical resonant circuit. In a further aspect, in the tuned position, the primary passive electrical resonant circuit, in response to an energizing signal produced by an ex-vivo source of RF energy, is configured to generate a sensor signal characterized by a resonant frequency that is indicative of the characteristic.

Abstract: The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency or set of frequencies and a predetermined amplitude. The energizing signal is coupled to the sensor via magnetic coupling and induces a current in the sensor which oscillates at the resonant frequency of the sensor. The system receives the ring down response of the sensor via magnetic coupling and determines the resonant frequency of the sensor, which is used to calculate the measured physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal.

Abstract: A nondestructive inspection apparatus includes a sensor unit for detecting vibrations transmitted through a test object from a vibration generator and a signal input unit for extracting a target signal from an electric signal outputted from the sensor unit. An amount of characteristics extracting unit is also included for extracting multiple frequency components from the test signal as an amount of characteristics. Further, a decision unit has a competitive learning neural network for determining whether the amount of the characteristics belongs to a category, wherein the competitive learning neural network has been trained by using training samples belong to the category representing an internal state of the test object, wherein distributions of membership degrees of the training samples are set in the decision unit.

Abstract: Devices and methods of the invention can be used in many industries, including: utilities, agriculture, food, textile, pharmaceutical, photovoltaic and semiconductor, medical devices, chemical and petro-chemical, material science, and defense, where monitoring and/or analysis of various properties of materials are desired.

Abstract: A structural health monitoring system and method uses a resonant transmission line sensor. A resonant transmission line sensor, which includes one or more sensor conductors and a dielectric material disposed at least proximate the one or more sensor conductors, is coupled to the structure. The dielectric material exhibits a dielectric constant that varies when at least a portion of the transmission line sensor is subjected to one or more stimuli. One or more resonant frequencies of the transmission line sensor are determined, and the determined one or more resonant frequencies are then correlated to the structural health of the structure.

Abstract: The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency or set of frequencies and a predetermined amplitude. The energizing signal is coupled to the sensor via magnetic coupling and induces a current in the sensor which oscillates at the resonant frequency of the sensor. The system receives the ring down response of the sensor via magnetic coupling and determines the resonant frequency of the sensor, which is used to calculate the measured physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal.

Abstract: It is an object to provide a test method of a process, an electric characteristic, and a mechanical characteristic of a structure body in a micromachine without contact. A structure body including a first conductive layer, a second conductive layer provided in parallel to the first conductive layer, and a sacrifice layer or a space provided between the first conductive layer and the second conductive layer is provided; an antenna connected to the structure body is provided; electric power is supplied to the structure body wirelessly through the antenna; and an electromagnetic wave generated from the antenna is detected as a characteristic of the structure body.

Abstract: A resonance electric current detection apparatus is disclosed. The above apparatus comprises a detection unit which detects an electric current by a resonance of an inductor L and a capacitor C and outputs to a control unit, and a control unit which controls an electric current detected by the detection unit. With the above construction, It is possible to easily perform a LC resonance electric current control, a speaker network resonance control, an automatic gain control and a LED control by forming the detected resonance electric current as a load circuit or controlling a surge voltage which is generated in a non-load state.

Abstract: A proximity and contact sensor (10) is provided with a sensor element (11) and a detection circuit (16). The sensor element is provided with a matrix (13) in which coil-shaped carbon fibers (12) are dispersed. A high-frequency oscillation circuit (19) of the detection circuit (16) supplies the sensor element with a high-frequency signal. A detector (22) in the detection circuit (16) receives an output signal from the sensor element (11) and detects proximity of an object (24). In one example, the coil-shaped carbon fibers (12) are contained in the matrix by 1 to 20% by weight. In another example, a high-frequency oscillation circuit generates a high-frequency signal of 100 to 800 kHz.

Abstract: The invention relates to MEMS resonators. In one embodiment, an integrated resonator and sensor device includes a micro-electromechanical system (MEMS) resonator, and an anchor portion coupled to the MEMS resonator and configured to allow resonance of the MEMS resonator in a first plane of motion and movement of the MEMS resonator in a second plane of motion. In other embodiments, additional apparatuses, devices, systems and methods are disclosed.

Abstract: The present invention discloses a non-destructive on-line method and a system for measuring predetermined physical, electrochemical, chemical and/or biological (PPECB) state transformation of a substance.

Abstract: A capacitive ultrasonic transducer includes a flexible layer, a first conductive layer on the flexible layer, a support frame on the first conductive layer, the support frame including a flexible material, a membrane over the support frame being spaced apart from the first conductive layer by the support frame, the membrane including the flexible material, a cavity defined by the first conductive layer, the support frame and the membrane, and a second conductive layer on the membrane.

Abstract: According to some embodiments, motor-tuned nuclear magnetic resonance (NMR) probes may be tuned manually without overcoming the tuning motor holding force. An NMR probe includes a switchable manual-mode/motor-driven mode capacitance-adjustment assembly for adjusting the capacitance of a variable capacitor connected to an NMR RF coil. The capacitance-adjustment assembly includes a tuning shaft coupled to the variable capacitor through a gear assembly, and a mode-switching coupler coupled to the tuning shaft. The mode-switching coupler includes a first terminal coupled to a piezoelectric motor, and a second terminal coupled to the tuning shaft. In the manual mode, a user pushes up the tuning shaft, decoupling the two terminals of the mode-switching coupler and thus decoupling the motor from the tuning shaft. The user then manually rotates the tuning shaft. In the motor-driven mode, a spring tensioner presses the two terminals of the mode-switching coupler together, coupling the motor to the tuning shaft.

Abstract: A method is disclosed for calibrating a capacitance of an apparatus for measuring dielectric properties of a part. The apparatus includes an electrically grounded chamber, a lower electrode disposed within the chamber and connected to a radiofrequency (RF) transmission rod, an electrically grounded upper electrode disposed within the chamber above the lower electrode, and a variable capacitor connected to control transmission of RF power through the RF transmission rod to the lower electrode. A method is also disclosed for determining a capacitance of a part through use of the apparatus. A method is also disclosed for determining a dielectric constant of a part through use of the apparatus. A method is also disclosed for determining a loss tangent of a part through use of the apparatus.

Abstract: A sensor system includes a first sensor, a second sensor, and an analyzer circuit, the first sensor including a first seismic mass having a first resonance frequency and the second sensor including a second seismic mass having a second resonance frequency, and the analyzer circuit being provided for analyzing a first output signal of the first sensor as well as a second output signal of the second sensor and, moreover, the first resonance frequency being unequal to the second resonance frequency.

Abstract: A diagnostic tool for performing electrical measurements to calibrate a plasma processing chamber probe is provided. The diagnostic tool includes an RF generator. The diagnostic tool also includes a first impedance circuit. The first impedance circuit is a voltage-load network, configured to deliver RF voltage outputs from the RF generator for voltage measurements when RF power from the RF generator is delivered to the first impedance circuit. The diagnostic tool further includes a second impedance circuit. The second impedance circuit is a current-load network, configured to deliver RF current outputs from the RF generator for current measurements when the RF power from the RF generator is delivered to the second impedance circuit. The diagnostic tool further includes a coaxial switch network arrangement configured to provide switchable RF delivery paths to deliver the RF power from the RF generator to one of the first impedance circuit and the second impedance circuit.

Abstract: The invention relates to MEMS resonators. In one embodiment, an integrated resonator and sensor device comprises a micro-electromechanical system (MEMS) resonator, and an anchor portion coupled to the MEMS resonator and configured to allow resonance of the MEMS resonator in a first plane of motion and movement of the MEMS resonator in a second plane of motion. In other embodiments, additional apparatuses, devices, systems and methods are disclosed.

Abstract: A system and apparatus for providing an in-vivo assessment of relative movement of an implant that is positioned in a living being is provided that comprises a first assembly and a second assembly that are positioned within the living being. The first assembly comprises a passive electrical resonant circuit that is configured to be selectively electromagnetically coupled to an ex-vivo source of RF energy and, in response to the electromagnetic coupling, generates an output signal characterized by a frequency that is dependent upon a distance between the first assembly and the second assembly at the time of the electromagnetic coupling.

Abstract: A generator generates radio-frequency electromagnetic radiation to a resonator whose resonance frequency is affected by a characteristic to be measured of an object to be measured. A receiver receives radio-frequency electromagnetic radiation from the resonator and a signal processing unit searches for a resonance frequency of the resonator for measuring the characteristic to be measured. The generator comprises a digital frequency synthesizer for scanning a frequency of radio-frequency electromagnetic radiation to be applied to the resonator over a desired frequency band by using discrete measuring frequencies.

Abstract: The exemplary embodiments of the invention provide techniques that assist in the absorption, reduction or elimination of the resonance of unwanted cavity modes in a cavity measurement system, such as a cylindrical TE0,n cavity measurement system used to measure various dielectric properties of a dielectric sample, for example. One non-limiting, exemplary system includes: sidewalls; a first endplate; a second endplate disposed opposite the first endplate so as to define a cavity bounded by the sidewalls, the first endplate and the second endplate; and first and second radio frequency (RF) coupling receptacles coupled to at least one of the sidewalls, the first endplate or the second endplate, wherein the first and second RF coupling receptacles are configured to pass a RF signal through the cavity. The first endplate has a plurality of conducting loops disposed on a surface facing the second endplate.

Abstract: A method and system is disclosed that can be used to directly detect and analyze an electric signal electrostatically induced a semi-conductive or conductive element at resonance. Through detection of the changes in the characteristics of the signal from the element, the disclosed devices can detect, for instance, presence of chemical/biological species in a sample or measure physical parameters of a sample such as pressure/acceleration, magnetic force, temperature, and/or extremely small masses. The disclosed systems include one or more micro- or nano-sized elements. Through modulation of an electric charge on a counter-electrode that is located at a pre-determined distance from the element, a modulating charge can be induced upon the element. Resonance can be directly detected via electronic monitoring of the induced signal for the higher harmonics of the natural resonant frequency.

Abstract: The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency or set of frequencies and a predetermined amplitude. The energizing signal is coupled to the sensor via magnetic coupling and induces a current in the sensor which oscillates at the resonant frequency of the sensor. The system receives the ring down response of the sensor via magnetic coupling and determines the resonant frequency of the sensor, which is used to calculate the measured physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal.