Iowa State University Research Foundation Inc

Other

Amvac Chemical Corporation

American Chemical Corporation

Sensors That Count, L.l.c.

Robert J Weber

Larry M Conrad

Mani Mina

Stanley G Burns

Marwan M Hassoun

Ratnesh Kumar

Russell W-c Chung

Jin-Wei Tioh

Richard L Willham

Rashmi Bahuguna

David C Jiles

John D Verhoeven

Steve D Braymen

Gunjan Pandey

Sasha N Kemmet

Philip H Thompson

Shannon Wanner

Charles F Campbell

Wing C Chung

Sanyi Zhan

Hsin-Jan Fu

Yet-zen Liu

Kanishka Aman Singh

Saalini Sekar

Sasha N Kemmet Oster

Chieh-Hsiao Wang

An electric measurement method and apparatus for detecting a mass by an electric capacity (permittivity) or a material's dielectric constant, or alternatively, electric inductance (permeability). The mass may be any phase or combination of phases. The mass may be stationary or flowing. It may comprise discrete particles such as grain, or manufactured products such as ball bearings or threaded fasteners, etc. The mass may be a flow element in a rotameter or similar flow measurement device. The sensor comprises a volume which may be completely full or only partially full of the material. The material may be discrete components or a continuum. Sensor signals may be received by existing planter monitoring systems. In some embodiments the flow sensors are positioned external to the application port. In some embodiments sensors may be utilized which are responsive to the refractive index variation of specific chemicals.

Flow sensor based on electrical capacity

Agricultural product application system and method thereof

The invention relates to a bistable piezoelectric cantilever-based vibration energy harvester that increases the energy harvested over a broad frequency of vibrations by introducing bistability to the cantilever through use of two repelling magnets, one mounted on the cantilever and one at a location facing the first. This increases the amplitude and velocity of cantilever vibration, hence harvested power, while nonlinearity makes the system efficient over almost the entire range of frequencies, lower than the natural resonant frequency of the linear version without the magnets. Such improved performance is seen while the cantilever remains in the bistable mode. To broaden the range of vibration amplitudes over which the harvester continues to operate in bistable mode, the harvester includes a mechanical way of tuning the magnetic force, by spring-loading the magnet facing the mounted one, enabling self-adjustment of the distance between the magnets automatically that favors bistable operation over a larger range of excitations, and that too without needing any extra energy.

Broad spectrum and wide amplitude range vibration energy harvester: bistable piezoelectric transduction, synchronized extraction, self-actuated adaptation

A soil sensor includes a housing, an antenna disposed within the housing, a measurement circuit disposed within the housing and operatively connected to the antenna, the circuit configured to measure impedance of soil at a plurality of different frequencies using the antenna as a sensor electrode, and a wireless interface disposed within the housing and operatively connected to the antenna and configured for wireless communications over the antenna at its communications frequency.

Low RF-band impedance spectroscopy based sensor for in-situ, wireless soil sensing

A pre-pulsed magnetic field generation circuit for a fiber-based, magneto-optic (MO) optical modulator or switch for use in an interferometer is provided. The pre-pulsed magnetic field is used to control the amount of rotation in the state of polarization (SOP), and therefore, the ON-OFF extinction ratio. The circuit includes a pair of amplifier circuits that control the current through a coil to generate the pre-pulsed magnetic field. One amplifier controls a magnitude of a steady state portion of the magnetic field, while the other controls both the amplitude and duration of a pre-pulse portion of the magnetic field.

Advanced drive circuitry for Sagnac interferometric switch utilizing faraday rotation

A fiber-based, magneto-optic (MO) optical modulator or switch based on Sagnac interferometry is provided. The system uses a magneto-optic Faraday rotator (MOFR) to produce optical modulation with low magnetic fields. The Sagnac geometry allows for increased modulation at lower fields than traditional MO modulators. This switch uses the MOFR to create different states of polarization in counter-propagating waves, which results in interference at the output port. A magnetic field is used to control the amount of rotation in the state of polarization (SOP), and therefore, the ON-OFF extinction ratio.

Sagnac interferometric switch utilizing faraday rotation

A passive RFID tag suitable for attachment to an electrically conductive surface is provided. The passive RFID tag includes a dielectric substrate, an RFID chip for storing data, and an RFID antenna structure operatively connected to the RFID chip wherein the RFID antenna structure comprises a slotted inverted L-shape. A method of manufacturing a passive RFID tag includes forming an antenna structure on a conductive layer, the antenna structure comprising a slotted inverted L-shape. The method further includes operatively connecting an RFID chip with the antenna structure. A method associated with a passive RFID tag includes providing a passive RFID tag. The passive RFID tag includes a dielectric substrate, an RFID chip for storing data, and an RFID antenna structure operatively connected to the RFID chip wherein the RFID antenna structure comprises a slotted inverted L-shape. The method further includes operatively connecting the passive RFID tag to a conductive surface.

Low profile metal-surface mounted RFID tag antenna

A method of spatial control of a phased array system having a plurality of antenna elements is provided. The method includes providing a baseband signal, baseband phase shifting the baseband signal to provide a plurality of baseband shifted signals for controlling phase of each of the plurality of antenna elements, upconverting each of the baseband shifted signals to a radio frequency signal, and applying each of the radio frequency signals to the plurality of antenna elements to thereby provide for spatial control of the phased array system. A hardware architecture for a phased array system is also provided.

Phased array system using baseband phase shifting

An integrated fiber optic switch based on the magneto-optic effect of magnetic materials suitable for optical fiber networks is presented. The switch is based on the Faraday Effect exhibited by magneto-optic materials. The all-fiber magneto-optic switch has a beam splitter at the input that splits an incoming signal into orthogonal polarized paths. Each path has at least one magneto-optic Faraday rotator (MOFR) controlled by a field. When the field is present, the polarization of the optical beam changes, thereby turning the switch on or off. A beam coupler couples the orthogonal polarized paths at the output of the all-fiber magneto-optic switch. The switch is constructed in the Mach-Zehnder configuration, utilizing two 3 dB couplers, isolators and MOFRs fabricated on silicon-on-insulator.

All fiber magneto-optic on-off switch for networking applications

A fiber optic switch based on the magneto-optic effect of magnetic materials is presented. Due to the optical fiber based construction of the switching device it is suitable for optical fiber networks The on-off function of the switch is useful for isolation and connection of node(s) from a fiber optical network without having to turn off a laser. The switch is based on the Faraday Effect exhibited by magneto-optic materials. The all-fiber magneto-optic switch has a beam splitter at the input that splits an incoming signal into orthogonal polarized paths. Each path has at least one magneto-optic Faraday rotator (MOFR) controlled by a field. When the field is present, the polarization of the optical beam changes, thereby turning the switch on or off depending on the initial polarization of the beam. A beam coupler couples the orthogonal polarized paths at the output of the all-fiber magneto-optic switch. The MOFR is a bismuth substituted iron garnet. In an alternate embodiment the switch is constructed in the Mach-Zehnder configuration, utilizing two 3 dB couplers, isolators and MOFRs. In an alternate embodiment the switch is fabricated on silicon-on-insulator.

The invention provides tapered-width micro-cantilevers and micro-bridges that give additional design parameters for controlling and synthesizing pull-in (i.e., actuation) voltages. The pull-in voltage of a tapered-width micro-cantilever is generally a function of the taper function of the width along the length, the initial width, and the length of the micro-cantilever. By controlling these design parameters, a specific pull-in voltage for a micro-cantilever is obtained. The formula for a pull-in voltage is determined based on the geometry of the micro-cantilever device and a plurality of derived pull-in voltages. The pull-in voltage is derived by iteratively solving a displacement vector as a function of applied voltage across the micro-cantilever device and setting the pull-in voltage to the voltage at which the solution does not converge. The formula is derived for linear-tapered width, parabolic-tapered width and exponential-tapered width micro-cantilevers.

Tapered-width micro-cantilevers and micro-bridges

A non-resonant electromagnetic energy sensor includes an electromagnetic energy source and an electromagnetic energy detector in communication with the interior volume of a measuring region through which an analyte passes. The electromagnetic energy detector detects the signal variations of the electromagnetic energy within the measuring region caused by the perturbation of the electromagnetic energy field due to the passage of the analyte therethrough and responds to these signal variations by generating output signals. These output signals may then be received by electronic circuitry designed for quantitative and/or qualitative detection of the flow of various substances including individual particles, particles flowing as a continuum, and non-turbulent fluids.

Non-resonant electromagnetic energy sensor

A non-resonant electromagnetic energy sensor which generates output signals upon the quantitative and/or qualitative detection of the flow of various substances including solid particles flowing as discrete individual particles or as a continuum, as well as the flow of liquids and/or gaseous substances. The non-resonant electromagnetic energy sensor may be interfaced with various types of electronic circuitry whereby the generated output signals may be used for monitoring a variety of flowing substances, for example, seed flow in an agricultural planter, crop yield on a combine harvester, and flow rates of liquids or gaseous fluids through conduits. The sensor comprises a housing having wall members defining a chamber having an interior volume. The sensor is designed to be interposed along a length of conduit through which the material or substance to be analyzed will pass. An electromagnetic energy source and an electromagnetic energy detector are in communication with the interior volume of the chamber. The electromagnetic energy source propagates non-resonant electromagnetic energy of a predetermined frequency and amplitude into a measuring region within the interior volume of the chamber. The electromagnetic energy detector detects the signal variations of the electromagnetic energy within the measuring region caused by the perturbation of the electromagnetic energy field due to the passage of the analyte therethrough and responds to these signal variations by generating output signals. These output signals may then be received by electronic circuitry designed for particular monitoring needs interfaced therewith.

A stacked thin film device structure grown on a substrate, the resonator structure comprising a thin film device comprising at least one piezoelectric crystal layer sandwiched between metallic electrodes, and constructed to have an acoustic response in a given frequency range, and an acoustical stack disposed between and joining the thin film device and the substrate and comprising multiple layers of material, each layer having a characteristic thickness and impedance and being composed of a non-lossless material, the characteristic thicknesses and impedances of the layers being adjusted to determine the input impedance presented to the thin film device, and thereby determining the acoustical coupling between the thin film device and the substrate.

Growing community of inventors

Boone, IA, United States of America

Robert J Weber