Abstract: Acoustic sensing utilizing a cantilever structure coupled about at least one side of said cantilever to a base substrate, wherein said cantilever includes a piezoelectric section and has at least one acoustic wave device on a portion of the cantilever, wherein a flexure of the cantilever produces force-frequency effects measurable by the acoustic wave device. According to one embodiment, the cantilever sensor uses the flexure-frequency effect as measured by an acoustic wave device to sense a target matter. According to one embodiment, a sensing material is disposed on at least a portion of at least one surface of the cantilever.

Abstract: A coating providing high abrasion and chemical resistance composed of a barrier layer from vanadium, molybdenum, niobium, tantalum and the like, and an outer layer of diamond-like carbon. The coating is especially applicable for acoustic wave device (AWD) based sensors, and for passivating an electrode such as an electrode deposited on the AWD sensing area. The coating provides excellent mechanical and acoustical characteristics for coating acoustic wave devices allowing the sensor to operate in harsh environments.

Abstract: A composite acoustic wave device (AWD) which is adapted for operation at high ambient pressures is provided. The AWD comprises two piezoelectric plates in back to back relationship, with electrodes disposed between the plates. The plates are bonded so as to neutralize the effects of external pressure. Further disclosed is a sensor utilizing the AWD and methods for utilizing such AWD for physical measurements in high pressure environments. An optional cavity formed between the piezoelectric plates offers the capability to measure the pressure and to further neutralize the residual effects of the pressure on measurement accuracy.

Abstract: Reflective and slanted array channelized sensor arrays having a broadband source providing acoustic energy to a reflective or slanted array that reflects a portion of the incident signal to one or more sensing films wherein the response is measured.

Abstract: A system and a method for providing information on two of the three variables, density (?), viscosity (?), and elastic modulus (c) of a fluid, such that independent knowledge of one variable allows the remaining two variables to be measured by a single sensor. The present invention relies on the interaction of a predominantly shear horizontal acoustic wave device (“quasi-shear-horizontal”) with the fluid, so as to measure subtle differences in the interaction of two or more acoustic resonance states or waveguide modes of a multi-mode resonator or waveguide, and to derive the desired fluid characteristics therefrom. The most preferred embodiment is a dual-mode coupled resonator filter geometry with one resonant mode having a high degree of symmetry and the other having a high degree of anti-symmetry.

Abstract: An acoustic wave sensor employs an electromagnetic device (EMD) to transduce and amplify the response of an impedance element to a physical measurand. One embodiment uses a magnetic field sensor employing a microelectromechanical system (MEMS) capacitor to affect a change in the response of a SAW filter.

Abstract: An in-line SAW resonator employs an asymmetric adjustment of the Bragg frequencies of the left outer reflector and right outer reflector where the degree of periodicity shift and the relative direction of the frequency shift are calculated to move the peaks of the acoustic standing wave trapped between the gratings to coincide with the optimized centers of transduction of one or more interdigital transducers (IDTs) without the need for undesirable breaks in the periodicity or the use of reflectionless IDTs.

Abstract: A sensor, method and system, for measuring certain characteristics of a fluid. The sensor utilizes a piezoelectric device having at least two tightly coupled resonators providing a two pole electric transfer function responsive to an electrical signal coupled to the input resonator. The piezoelectric sensor has a textured entrapment layer, constructed to entrap a known volume of fluid and impart motion to the entrapped fluid as well as to surrounding non-trapped fluid. The common mode frequency shift of the two resonant frequencies is related to mass loading due to the entrapped fluid, while the energy absorbed by the fluid, or a phase shift of one of the resonant frequencies, is related to the viscosity/density product of the fluid. Extracting the viscosity is a matter of mathematical manipulation. By controlling the energy level of the input electrical signal, the viscosity measurement may be conducted at a predetermined shear rate.

Abstract: An in-line SAW resonator employs an asymmetric adjustment of the Bragg frequencies of the left outer reflector and right outer reflector where the degree of periodicity shift and the relative direction of the frequency shift are calculated to move the peaks of the acoustic standing wave trapped between the gratings to coincide with the optimized centers of transduction of one or more interdigital transducers (IDTs) without the need for undesirable breaks in the periodicity or the use of reflectionless IDTs.

Abstract: Reflective and slanted array channelized sensor arrays having a broadband source providing acoustic energy to a reflective or slanted array that reflects a portion of the incident signal to one or more sensing films wherein the response is measured.

Abstract: Acoustic sensing utilizing a bridge structure coupled about a portion of at least two sides of said bridge to a base substrate, wherein said bridge includes a piezoelectric section and has at least one active acoustic region proximate said bridge. A sensing material is disposed on at least a portion of at least one surface of the bridge, wherein the bridge produces stress effects measurable by an acoustic wave device located in the active acoustic region. According to one embodiment, the stress effects are measured by an acoustic wave device to sense a target matter. As target molecules accumulate on a sensing film affixed to at least a portion of the bridge, stress is produced in the bridge inducing a frequency change measured by an acoustic wave device.

Abstract: A surface acoustic wave device is provides and comprises a flexible substrate having a first side and a piezoelectric film attached to at least a portion of the first side of the flexible substrate. The piezoelectric film can have a first side and a second side. A surface acoustic wave circuit can adjoin at least a portion of the first side of the piezoelectric film. These devices can comprise thin and flexible substrates, such as polyimide to make the devices flexible. If adhesive is applied to the back of devices constructed in accordance with the invention, such devices can be adhered to almost any surface, even a curved surface. The devices of the present invention can be easily integrated with other devices.

Abstract: Acoustic sensing utilizing a cantilever structure coupled about at least one side of said cantilever to a base substrate, wherein said cantilever includes a piezoelectric section and has at least one acoustic wave device on a portion of the cantilever, wherein a flexure of the cantilever produces force-frequency effects measurable by the acoustic wave device. According to one embodiment, the cantilever sensor uses the flexure-frequency effect as measured by an acoustic wave device to sense a target matter. According to one embodiment, a sensing material is disposed on at least a portion of at least one surface of the cantilever.

Abstract: An apparatus and a method for controlling the shear rate at which an acoustic wave device measures viscosity, by utilizing an automatic level control or an automatic gain control circuit to control power input to the sensor as a function of the sensor's output power. Further improvement is provided by measuring the input power and combining the input power and output power measurements, preferably by averaging, to control the input power to the sensor. A method is also provided for characterizing the fluid under test by providing a set of viscosity measurements at various shear rates.

Abstract: A diode detector comprising a detector network adapted to detect and multiply the detected voltage coupled to a divider network that comprise diodes in equal number to the number of diodes in the detector network, provides a passive detector applicable to any application requiring a small, efficient, high output, inexpensive temperature compensated detector for use as demodulator or as power to voltage converter. Integrating a portion of the divider network in the detector/multiplier network allows control over the minimum input impedance of the detector.

Abstract: A method for controlling the shear rate at which an acoustic wave device measures viscosity by calculating the shear rate as a function of the characteristic rate of quartz movement in response to a given input transducer power level and the viscosity of the fluid and then by adjusting the input transducer power level to obtain the desired shear rate for the viscosity measurement by optimizing the power level. Related aspects of the invention provide for methods for characterizing viscoelastic fluids at a plurality of predetermined shear rates using a plurality of optimized power levels, a plurality of sensor designs, or a plurality of both optimized power levels and sensor designs.

Abstract: A method for measuring viscosity and shear rate at which the measurement is performed is provided, by utilizing an acoustic wave sensor, and calculating the shear rate as a function of the characteristic rate of quartz movement in response to a given power transmitted to a fluid, and the viscosity of the fluid. Related aspects of the invention provide for methods for controlling the shear rate at which a viscosity measurement is performed, and characterizing viscoelastic fluids at a plurality of shear rates.

Abstract: An acoustic wave device, which utilizes multiple localized reflections of acoustic wave for achieving an infinite impulse response while maintaining high tolerance for dampening effects, is disclosed. The device utilized a plurality of electromechanically significant electrodes disposed on most of the active surface. A plurality of sensors utilizing the disclosed acoustic wave mode device are also described.

Abstract: A diode detector comprising a detector network adapted to detect and multiply the detected voltage coupled to a divider network that comprise diodes in equal number to the number of diodes in the detector network, provides a passive detector applicable to any application requiring a small, efficient, high output, inexpensive temperature compensated detector for use as demodulator or as power to voltage converter.

Abstract: A diode detector comprising a detector network adapted to detect and multiply the detected voltage coupled to a divider network that comprise diodes in equal number to the number of diodes in the detector network, provides a passive detector applicable to any application requiring a small, efficient, high output, inexpensive temperature compensated detector for use as demodulator or as power to voltage converter.