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Theodorus S J Lammerink - One of the best experts on this subject based on the ideXlab platform.

  • optimization of a micro coriolis mass Flow Sensor using lorentz force actuation
    2012
    Co-Authors: Jarno Groenesteijn, Remco J. Wiegerink, Theodorus S J Lammerink, J Haneveld, Joost Conrad Lotters
    Abstract:

    In this paper we present Finite Element models to optimize the Lorentz force actuation of a micro Coriolis mass Flow Sensor. These models specify six different configurations for the permanent magnets used to create the magnetic field for the actuation. The models are used to compare the various configurations in terms of the strength of the Lorentz force used for actuating the vibrational modes, and in terms of the sensitivity to misalignment of the magnetic field of the magnets. The simulations show that the Lorentz force actuation can be increased significantly by improving the placement of the magnets and that the actuation is insensitive to misalignment of the tube in relation to the magnetic field. By applying the models to a fabricated Sensor, the magnetic field outside the Sensor area has been reduced by 6 orders of magnitude. Due to the smaller size of the new permanent magnets, the footprint of the chip, including actuation, has been reduced by a factor 3. The models of two magnet configurations without misalignment have been validated with measurements.

  • advancements in technology and design of biomimetic Flow Sensor arrays
    2009
    Co-Authors: C M Uinink, Remco J. Wiegerink, Theodorus S J Lammerink, R K Jaganatharaja, M J De Boe, Erwi Erenscho, M L Kolste, Gijsbertus J M Krijne
    Abstract:

    This paper reports on recent developments to increase the performance of biomimetic Flow-Sensor arrays by means of several technological advancements in the fabrication procedures and corresponding Sensor design optimizations. Advancements include fabrication procedures with higher process latitude and geometrical modifications of several parts of the Flow Sensor. The conclusive measurements in this paper support our Sensor-model predictions for a 100-fold increase in acoustic sensitivity (down to oscillating Flow amplitudes in the order of 1 mm·s-1) translating to substantially higher capacitive outputs in comparison to our first-generation biomimetic Flow-Sensor arrays.

  • low drift Flow Sensor with zero offset thermopile based power feedback
    2008
    Co-Authors: M Dijkstra, Remco J. Wiegerink, Theodorus S J Lammerink, M J De Boer, J W Berenschot, Miko Elwenspoek
    Abstract:

    A thermal Flow Sensor has been realised consisting of freely-suspended silicon-rich silicon-nitride microchannels with an integrated Al/poly-Si++ thermopile in combination with up- and downstream Al heater resistors. The inherently zero offset of the thermopile is exploited in a feedback loop controlling the dissipated power in the heater resistors, eliminating inevitable influences of resistance drift and mismatch of the thin-film metal resistors. The control system cancels the Flow-induced temperature difference across the thermopile by controlling a power difference between both heater resistors, thereby giving a measure for the Flow rate. The Flow Sensor was characterised for power difference versus water Flow rates up to 1.5 mul-min-1, being in good agreement with a thermal model of the Sensor, and the correct low-drift operation of the temperature-balancing control system has been verified.

  • highly sensitive micro coriolis mass Flow Sensor
    2008
    Co-Authors: J Haneveld, Theodorus S J Lammerink, M J De Boer, Mindert Dijkstra, H Droogendijk, Remco J. Wiegerink
    Abstract:

    We have realized a micromachined micro Coriolis mass Flow Sensor consisting of a silicon nitride resonant tube of 40 mum diameter and 1.2 mum wall thickness. Actuation of the Sensor in resonance mode is achieved by Lorentz forces. First measurements with both gas and liquid Flow have demonstrated a resolution in the order of 10 milligram per hour. The Sensor can simultaneously be used as a density Sensor.

  • Miniaturized thermal Flow Sensor with planar-integrated Sensor structures on semicircular surface channels
    2008
    Co-Authors: Martijn Dijkstra, Remco J. Wiegerink, Theodorus S J Lammerink, J W Berenschot, Miko Elwenspoek
    Abstract:

    A calorimetric miniaturized Flow Sensor was realized with a linear Sensor response measured for water Flow up to Flow rates in the order of 300 nl min-1. A versatile technological concept is used to realize a Sensor with a thermally isolated freely suspended silicon-rich silicon-nitride microchannel directly below the substrate surface. The microchannel concept allows for the planar integration of Sensor structures in close proximity to the fluid, while chemical-resistant fluidic connections can be made directly on top of the microchannel, without introducing large dead-volumes. The realized Flow Sensor consists of a microchannel with low hydraulic resistance and 4.5 nl total fluid volume. A pressure driven Flow setup was used to force water through the microchannel, measuring output sensitivity in the order of 0.2 μV/(nl min-1) for Flows up to 300 nl min-1. The measured Sensor output is in close agreement with results obtained from both a detailed and an approximate numerical model of the Sensor. © 2008.

Remco J. Wiegerink - One of the best experts on this subject based on the ideXlab platform.

  • optimization of a micro coriolis mass Flow Sensor using lorentz force actuation
    2012
    Co-Authors: Jarno Groenesteijn, Remco J. Wiegerink, Theodorus S J Lammerink, J Haneveld, Joost Conrad Lotters
    Abstract:

    In this paper we present Finite Element models to optimize the Lorentz force actuation of a micro Coriolis mass Flow Sensor. These models specify six different configurations for the permanent magnets used to create the magnetic field for the actuation. The models are used to compare the various configurations in terms of the strength of the Lorentz force used for actuating the vibrational modes, and in terms of the sensitivity to misalignment of the magnetic field of the magnets. The simulations show that the Lorentz force actuation can be increased significantly by improving the placement of the magnets and that the actuation is insensitive to misalignment of the tube in relation to the magnetic field. By applying the models to a fabricated Sensor, the magnetic field outside the Sensor area has been reduced by 6 orders of magnitude. Due to the smaller size of the new permanent magnets, the footprint of the chip, including actuation, has been reduced by a factor 3. The models of two magnet configurations without misalignment have been validated with measurements.

  • advancements in technology and design of biomimetic Flow Sensor arrays
    2009
    Co-Authors: C M Uinink, Remco J. Wiegerink, Theodorus S J Lammerink, R K Jaganatharaja, M J De Boe, Erwi Erenscho, M L Kolste, Gijsbertus J M Krijne
    Abstract:

    This paper reports on recent developments to increase the performance of biomimetic Flow-Sensor arrays by means of several technological advancements in the fabrication procedures and corresponding Sensor design optimizations. Advancements include fabrication procedures with higher process latitude and geometrical modifications of several parts of the Flow Sensor. The conclusive measurements in this paper support our Sensor-model predictions for a 100-fold increase in acoustic sensitivity (down to oscillating Flow amplitudes in the order of 1 mm·s-1) translating to substantially higher capacitive outputs in comparison to our first-generation biomimetic Flow-Sensor arrays.

  • low drift Flow Sensor with zero offset thermopile based power feedback
    2008
    Co-Authors: M Dijkstra, Remco J. Wiegerink, Theodorus S J Lammerink, M J De Boer, J W Berenschot, Miko Elwenspoek
    Abstract:

    A thermal Flow Sensor has been realised consisting of freely-suspended silicon-rich silicon-nitride microchannels with an integrated Al/poly-Si++ thermopile in combination with up- and downstream Al heater resistors. The inherently zero offset of the thermopile is exploited in a feedback loop controlling the dissipated power in the heater resistors, eliminating inevitable influences of resistance drift and mismatch of the thin-film metal resistors. The control system cancels the Flow-induced temperature difference across the thermopile by controlling a power difference between both heater resistors, thereby giving a measure for the Flow rate. The Flow Sensor was characterised for power difference versus water Flow rates up to 1.5 mul-min-1, being in good agreement with a thermal model of the Sensor, and the correct low-drift operation of the temperature-balancing control system has been verified.

  • highly sensitive micro coriolis mass Flow Sensor
    2008
    Co-Authors: J Haneveld, Theodorus S J Lammerink, M J De Boer, Mindert Dijkstra, H Droogendijk, Remco J. Wiegerink
    Abstract:

    We have realized a micromachined micro Coriolis mass Flow Sensor consisting of a silicon nitride resonant tube of 40 mum diameter and 1.2 mum wall thickness. Actuation of the Sensor in resonance mode is achieved by Lorentz forces. First measurements with both gas and liquid Flow have demonstrated a resolution in the order of 10 milligram per hour. The Sensor can simultaneously be used as a density Sensor.

  • Miniaturized thermal Flow Sensor with planar-integrated Sensor structures on semicircular surface channels
    2008
    Co-Authors: Martijn Dijkstra, Remco J. Wiegerink, Theodorus S J Lammerink, J W Berenschot, Miko Elwenspoek
    Abstract:

    A calorimetric miniaturized Flow Sensor was realized with a linear Sensor response measured for water Flow up to Flow rates in the order of 300 nl min-1. A versatile technological concept is used to realize a Sensor with a thermally isolated freely suspended silicon-rich silicon-nitride microchannel directly below the substrate surface. The microchannel concept allows for the planar integration of Sensor structures in close proximity to the fluid, while chemical-resistant fluidic connections can be made directly on top of the microchannel, without introducing large dead-volumes. The realized Flow Sensor consists of a microchannel with low hydraulic resistance and 4.5 nl total fluid volume. A pressure driven Flow setup was used to force water through the microchannel, measuring output sensitivity in the order of 0.2 μV/(nl min-1) for Flows up to 300 nl min-1. The measured Sensor output is in close agreement with results obtained from both a detailed and an approximate numerical model of the Sensor. © 2008.

Euisik Yoon - One of the best experts on this subject based on the ideXlab platform.

  • low power bio inspired time stamp based 2 d optic Flow Sensor for artificial compound eyes of micro air vehicles
    2019
    Co-Authors: Seokjun Park, Hyunsoo Song, Sungyun Park, Euisik Yoon
    Abstract:

    We report a low-power, bio-inspired mixed-signal 2-D optic Flow Sensor to realize artificial compound eyes, which can provide a wide field of view (FoV) sensing capability for autonomous navigation of micro-air-vehicles (MAVs). Inspired by insect vision, a 2-D time-stamp algorithm has been developed to scale the number of deployable Sensors at low power. The fabricated Sensor estimates 16-b 2-D optic Flows of maximum 1.96 rad/s with FoV of 60° from the integrated mixed-signal algorithm core, which consumes only 243.3 pJ/pixel or $\sim 30~\mu \text{W}$ at 120 fps. In addition, the peripheral circuits for modular design have been integrated on chip to provide optic Flow data compression, wide-field integration (WFI), and serial peripheral interface (SPI). More than 25 Sensors can be connected in a single SPI bus and transmit the full resolution optic Flows. The fabricated prototype Sensor supports full resolution 2-D optic Flows from an array of $64\times 64$ pixels at 120 fps through a 3 MB/s SPI bus (4 wires total).

  • 7 2 243 3pj pixel bio inspired time stamp based 2d optic Flow Sensor for artificial compound eyes
    2014
    Co-Authors: Seokjun Park, Euisik Yoon
    Abstract:

    Miniaturized low-power artificial compound eyes in a small form factor and a low payload can be a promising approach to provide wide-field information for micro-air-vehicle (MAV) applications. Recently, research efforts have been made to realize bio-inspired artificial compound eyes to mimic the wide field of view (FoV) of insect visual organs by implementing photoreceptors to independently face different angles [1-2]. However, these approaches have drawbacks. They use complicated fabrication processes to form a hemispherical lens configuration and secure an independent optical path to each photoreceptor. We take a simple and practical approach to realize wide-field optic Flow sensing in a pseudo-hemispherical configuration by mounting a number of 2D array optic Flow Sensors on a flexible PCB module as shown in Figure 7.2.1. In this scheme, the 2D optic Flow Sensor should meet the requirements of MAV applications: extremely low power consumption while maintaining robust optic Flow generation. Conventional optic Flow algorithms, such as Lucas-and-Kanade, require huge amounts of numerical calculations; therefore, they require substantial digital hardware (CPU and/or FPGA), resulting in large power consumption [3-4]. As an alternative approach for low-power implementation, bio-inspired elementary motion detector (EMD) based algorithms (or neuromorphic algorithms) have been studied and implemented in analog VLSI circuits for autonomous navigation [5-6]. However, pure analog signal processing is easily susceptible to temperature and process variations and it is difficult to scale the pixel size or apply low-power design techniques because extensive analog processing is implemented in pixel-level circuits. In this work, we have devised and implemented a time-stamp-based optic Flow algorithm, which is modified from the conventional EMD algorithm to give an optimum partitioning of hardware blocks in analog and digital domains as well as assign adequate allocation of pixel-level, column-parallel, and chip-level processing. Temporal filtering, which may require huge hardware resources if implemented in the digital domain, remains in a pixel-level analog processing unit. Feature detection is implemented using digital circuits that are column parallel. The embedded digital core decodes the 2D time-stamp information into velocity using chip-level processing. Finally, the estimated 16b optic Flow data are compressed and transmitted to the host through a 4-wired Serial Peripheral Interface (SPI) bus.

  • An integrated mass Flow Sensor with on-chip CMOS interface circuitry
    1992
    Co-Authors: Euisik Yoon, Kensall D. Wise
    Abstract:

    A multielement monolithic mass Flow Sensor which developed for possible use in automotive and industrial process control applications is reported. The chip illustrates the use of a common microstructure (a thin dielectric window/diaphragm) for the simultaneous measurement of Flow velocity (rate), Flow direction, gas type, and pressure. These transducers are merged with on-chip interface electronics to amplify and multiplex the transducer signals, control on-chip actuators, perform self-test, reduce the number of external leads required, and demonstrate process compatibility with a p-well CMOS process. The on-chip circuitry also implements a bandgap Sensor for the measurement of ambient temperature. Thus, the chip simultaneously monitors all parameters needed for the computation of true mass Flow, requires only ten external leads, and delivers high-level buffered output signals. >

Miko Elwenspoek - One of the best experts on this subject based on the ideXlab platform.

  • low drift Flow Sensor with zero offset thermopile based power feedback
    2008
    Co-Authors: M Dijkstra, Remco J. Wiegerink, Theodorus S J Lammerink, M J De Boer, J W Berenschot, Miko Elwenspoek
    Abstract:

    A thermal Flow Sensor has been realised consisting of freely-suspended silicon-rich silicon-nitride microchannels with an integrated Al/poly-Si++ thermopile in combination with up- and downstream Al heater resistors. The inherently zero offset of the thermopile is exploited in a feedback loop controlling the dissipated power in the heater resistors, eliminating inevitable influences of resistance drift and mismatch of the thin-film metal resistors. The control system cancels the Flow-induced temperature difference across the thermopile by controlling a power difference between both heater resistors, thereby giving a measure for the Flow rate. The Flow Sensor was characterised for power difference versus water Flow rates up to 1.5 mul-min-1, being in good agreement with a thermal model of the Sensor, and the correct low-drift operation of the temperature-balancing control system has been verified.

  • Miniaturized thermal Flow Sensor with planar-integrated Sensor structures on semicircular surface channels
    2008
    Co-Authors: Martijn Dijkstra, Remco J. Wiegerink, Theodorus S J Lammerink, J W Berenschot, Miko Elwenspoek
    Abstract:

    A calorimetric miniaturized Flow Sensor was realized with a linear Sensor response measured for water Flow up to Flow rates in the order of 300 nl min-1. A versatile technological concept is used to realize a Sensor with a thermally isolated freely suspended silicon-rich silicon-nitride microchannel directly below the substrate surface. The microchannel concept allows for the planar integration of Sensor structures in close proximity to the fluid, while chemical-resistant fluidic connections can be made directly on top of the microchannel, without introducing large dead-volumes. The realized Flow Sensor consists of a microchannel with low hydraulic resistance and 4.5 nl total fluid volume. A pressure driven Flow setup was used to force water through the microchannel, measuring output sensitivity in the order of 0.2 μV/(nl min-1) for Flows up to 300 nl min-1. The measured Sensor output is in close agreement with results obtained from both a detailed and an approximate numerical model of the Sensor. © 2008.

  • Miniaturized Flow Sensor with planar integrated Sensor structures on semicircular surface channels
    2007
    Co-Authors: Martijn Dijkstra, M J De Boer, Remco J. Wiegerink, Theodorus S J Lammerink, J W Berenschot, Miko Elwenspoek
    Abstract:

    A calorimetric miniaturized Flow Sensor was realized with a linear Sensor response measured for DI water Flow from 40 nlmin-1 up to 300 nlmin-1. A versatile technological concept is used to realize a Sensor with thermally-isolated freely-suspended silicon-nitride microchannels directly below the substrate surface. The microchannel concept allows for the planar integration of Sensor structures in close proximity to the fluid. Chemical-resistant fluidic connections can be made directly on top of the microchannels, without introducing large dead-volumes. The realized Flow Sensor consists of a microchannel with low hydraulic resistance and small total fluid volume.

  • temperature balance micro Flow Sensor system based on a free oscillating differential power controller
    2001
    Co-Authors: Theodorus S J Lammerink, Remco J. Wiegerink, Miko Elwenspoek
    Abstract:

    A thermal Flow Sensor is designed and realized. The Sensor is built according to the Thermal Balance Anemometer concept and consists of a co-design of a oscillating differential power controller and the physical Sensor structure. With relative simple electronics a Flow-dependent-duty-cycle square wave output signal is generated which is directly readable by modern digital signal processors.

  • a new class of thermal Flow Sensors using spl delta t 0 as a control signal
    2000
    Co-Authors: Theodorus S J Lammerink, Gijsbertus J M Krijnen, N R Tas, Miko Elwenspoek
    Abstract:

    In this paper we propose a new anemometer principle. Next to the known Constant Power Anemometry (CPA) and the Constant Temperature Anemometry (CTA), here the Temperature Balanced Anemometry (TBA) is presented. A compact overview of thermal Flow Sensor system concepts is given. The new concept has important consequences for simple Flow Sensor calibration. The proposed concept is investigated using experiments on conventional thermal Flow Sensors. A micro Flow Sensor is presented in combination with an example of simple electronic interfacing circuitry.

R M White - One of the best experts on this subject based on the ideXlab platform.

  • mems capacitive Flow Sensor for natural gas pipelines
    2015
    Co-Authors: Son Nguyen, Igor Paprotny, Paul K Wright, R M White
    Abstract:

    Abstract This paper presents the design, fabrication, and experimental results of an in-plane MEMS capacitive Flow Sensor that uses the displacement of a micro-fabricated paddle caused by dynamic gas pressure for measuring the velocity of the Flow of surrounding gas. The fabrication process is simple; the prototype is fabricated on 100-μm device Silicon-On-Insulator wafers using only three photo-lithographic mask layers. The device area is 5.5 mm by 5.5 mm. A comb-drive capacitance is used as the transducer for the Flow Sensor. Measurements show that the output capacitance C is a quadratic function of the gas velocity v , C = k1 v 2  + k2 v  + Cp, where k1 = −8.5 fF/(m/s)2, k2 = 73.6 fF/(m/s) and Cp = 16 pF. The advantage of using a capacitive sensing mechanism is that it is virtually insensitive to changes in ambient temperature. Experimental results show that the output capacitance changed only slightly, about 0.21–0.34%, when the temperature changed from 23 °C to 43 °C. Simplicity of fabrication, combined with insensitivity to variations in ambient temperature makes this Sensor ideal for widespread deployment to monitor the Flow in natural gas pipelines.

  • in plane capacitive mems Flow Sensor for low cost metering of Flow velocity in natural gas pipelines
    2014
    Co-Authors: Son Nguyen, Igor Paprotny, Paul K Wright, R M White
    Abstract:

    This paper presents the design, fabrication, and experimental results of an in-plane capacitive MEMS Flow Sensor that uses the displacement of a micro-fabricated paddle caused by dynamic pressure for measuring the velocity of the Flow of surrounding gas. The fabrication process is simple; the device is fabricated on Silicon-On-Insulator wafers using only three photolithographic masks. A comb-drive capacitance is used as the transducer for the Flow Sensors. This capacitive mechanism is virtually insensitive to changes in ambient temperature. Simplicity of fabrication, combined with insensitivity to variations in ambient temperature makes this Sensor ideal for widespread deployment in natural gas pipelines.

  • integrated Flow Sensor for in situ measurement and control of acoustic streaming in flexural plate wave micropumps
    2000
    Co-Authors: Namtrung Nguyen, Audra H Meng, Justin Black, R M White
    Abstract:

    Abstract This paper presents the design, fabrication, and characterization of a micromachined Flow Sensor, which is integrated onto the flexural plate wave (FPW) micropump. The Flow Sensor and the FPW micropump represent a complex microfluidic system that is able to control the fluid Flow in the device. The system was designed using a commercial software package. The microfluidic system of a size of 10×10 mm was fabricated using common fabrication techniques. The micropump is made of an aluminum, piezoelectric zinc oxide, polysilicon, and low-stress silicon nitride membrane with a typical thickness of 1–3 μm. The thermal Flow Sensor consists of a polysilicon heater and polysilicon–aluminum thermopiles as temperature Sensors. The cold junctions of the thermopiles are located in a new design that will avoid the drift effect of the Flow Sensor. The results show expected Flow velocity–drive voltage characteristics.