Coriolis Mass Flow Sensor Research Articles

A highly stable, pressure-driven, flow control system based on Coriolis mass flow sensors for organs-on-chips

Stable delivery of liquids to microfluidic systems is essential for their reproducible functioning, especially when supplying flows to organs-on-chips – delicate living models that recreate human physiology on the microscale and thus can be used to reduce the need for animal testing. Most flow control systems are unable to sustain a robust and stable flow in longer experiments (>1 week), particularly those based on the ubiquitous syringe pump. Though easy to use, syringe pumps have no mechanism for actually measuring flow, let alone flow regulation with sensor feedback. We have developed a liquid delivery system based on the generation of flow by applying a constant air pressure to liquids in sealed containers. A flow of liquid is monitored by accurate measurement of mass flows (mg/min) using downstream Coriolis-based mass flow sensors. Measured mass flows provide fast feedback to integrated valves, with valves opening or closing slightly to increase or decrease solution flows to the organs-on-chips as required. This mass flow sensing principle is not affected by changes in the density, temperature, and viscosity of the liquids being displaced. This is in contrast to systems that use volumetric flow sensors, which require recalibration when these parameters change. The rationale behind using this principle for organs-on-chips, is that the stability provided by this flow control system allows for more control over growth of these mini-organs. We demonstrate the functionality of this system with three examples: 1) Fast stabilization (within seconds) under changing physical conditions; 2) Short-term stability (minutes to hours) of delivered flows in a microreactor with interconnected inlets; and 3) Long-term stability (>1 week) of cell medium flows to a living organ-on-a-chip. Two categories of organs-on-chips (OOCs) can be distinguished: 1) solid OOC are designed for three-dimensional cell or tissue constructs that interact with each other and their surroundings, and 2) barrier-type OOC contain a selective cellular barrier between two compartments as do many barriers in the body. The latter of these two types is the most challenging to culture and maintain as they are very sensitive to variations in flow and pressure surges. The flow control system presented in this work provides a great improvement compared to the use of syringe pumps and volumetric flow sensors in OOC studies. The novelty of this work lies in the long-term stability use of this system for organs-on-chips, maintaining stability for short to very long periods of time without compromising the barrier function of the organ-on-chip by pressure surges, bacterial contamination, or other undesired effects from the flow delivery system.

Modeling, Fabrication, and Testing of a 3D-Printed Coriolis Mass Flow Sensor.

This paper presents the modeling, fabrication, and testing of a 3D-printed Coriolis mass flow sensor. The sensor contains a free-standing tube with a circular cross-section printed using the LCD 3D-printing technique. The tube has a total length of 42 mm, an inner diameter of about 900 µm, and a wall thickness of approximately 230 µm. The outer surface of the tube is metalized using a Cu plating process, resulting in a low electrical resistance of 0.5 Ω. The tube is brought into vibration using an AC current in combination with a magnetic field from a permanent magnet. The displacement of the tube is detected using a laser Doppler vibrometer (LDV) that is part of a Polytec MSA-600 microsystem analyzer. The Coriolis mass flow sensor has been tested over a flow range of 0-150 g/h for water, 0-38 g/h for isopropyl alcohol (IPA), and 0-50 g/h for nitrogen. The maximum flow rates of water and IPA resulted in less than a 30 mbar pressure drop. The pressure drop at the maximum flow rate of nitrogen is 250 mbar.

Free Suspended Thin-Walled Nickel Electroplated Tubes for Microfluidic Density and Mass Flow Sensors

In this paper, a novel fabrication method is proposed for microfluidic tubes with a large diameter, circular cross-section, and thin wall. These properties make the tubes especially suitable for density sensors and Coriolis mass flow sensors, because of the resulting low tube mass, low-pressure drop, and low pressure-dependence of the tube shape. A demonstrator sensor was fabricated and the first measurement results of fluid density and mass flow are presented. The low-cost fabrication method is based on electroplating technology and results in tubes with a near-perfect circular cross-section. Diameters ranging from 120 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> to 1 mm and wall thicknesses from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8~\mu \text{m}$ </tex-math></inline-formula> to 60 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> have been achieved. For the demonstrator sensor presented in this paper a freely suspended tube was realized with a total length of 37 mm, a diameter of 600 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> , and a wall thickness of 20 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> . Density measurements were performed using various gases, liquids, and liquid mixtures at 21°C to 23°C lab temperature. The accuracy of the measured densities of gases such as nitrogen, argon, and helium is 5%. For liquids including DI water, isopropyl alcohol (IPA), and their various mixtures an accuracy of 0.5% was obtained. Preliminary mass flow rate measurements were performed with water and isopropyl alcohol up to 30 g/h with less than 30 mbar pressure drop thanks to the large tube diameter. [2021-0179]

Design, Fabrication, and Characterization of a Micro Coriolis Mass Flow Sensor Driven by PZT Thin Film Actuators

A micro Coriolis flow sensor accurately measures small mass flows without being affected by properties of the fluid. This paper presents a micro Coriolis mass flow sensor driven by PZT thin film piezoelectric actuators, which allows a combination of large actuation force, low power dissipation and virtually no self-heating. The sensor was fabricated using surface channel technology, resulting in a tube diameter of 40 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> and a thin silicon-rich silicon nitride tube wall of 1.2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> thick, with a few additional steps to form the integrated piezoelectric actuators. The integrated actuators can actuate the sensor into both swing mode and twist mode. Both actuation modes were evaluated for different fluids and the results are presented in this paper. In the case of swing mode actuation, an optical readout was used to detect the resulting Coriolis movement, resulting in a relatively low sensitivity. In the case of twist mode actuation, a capacitive readout was used and, in comparison to previously published devices, a high mass flow sensitivity was achieved thanks to an optimized readout design. The measurement results show the read-out noise has a standard deviation of 0.15% of the full scale of 1.8 gh <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> when actuated in the twist mode. [2020-0392]

FEA design and analysis of flow sensor

In this research article a resonating tube was designed for Coriolis mass flow Sensor (CMFS) and sensor locations was varied. Resonant tube was designed to withstand maximum pressure with governing equations of coupled fluid structure problems. What is the result of sensor location on phase shift is the main goal of this research study. For omega type resonant tube from the base of vertical omega tube, the sensor locations have been varied from 60 mm to 120 mm in the present research article. CMFS is based on Coriolis Effect principle. For modelling of tube design, pro-E was used, and for analysis purpose Ansys 14.5 was used. Sensor locations and phase shift simulation results have been validated with experimental results. With the help of experimental results validation of sensor locations and phase shift simulations has been done. Omega type test configuration having L = 300 and D = 400 mm was used for experimentation for tube materials. The maximum values of phase shift was observed around 120 mm sensor location for 0.1 and 0.2 kg/s mass flow rate. It was observed from result that phase shift values are linearly varying with all range of mass flow rates. The resonant frequency is 24 Hz obtained from modal analysis for copper omega resonating tube.

Positional optimisation of twin-S shape CMFS in stainless steel tube

Modelling and simulation of atwin S-shape coriolis mass flow sensor within a stainless tube to determine the optimum phase-shift is the main focus of this study. The mass flow sensor is positioned inside a stainless steel tube. To measure the mass flow rate CMFS is placed inside the tube. The interlinkage within the fluid flow and vibration results in phase shift owing to the twist shape. Optimized sensor position is obtained by computing the mass flow rate and calculating phase shift at varied sensor arrangements within the tube. The modelling of the Coriolis mass flow sensor is done using version 5 of CATIA and ANSYS version 16.2 was used for simulation. The simulation for the System coupling is run for the material with flow velocities taken as 20 m/sec. The displacement is calculated at the different sensor positions. ThE optimized design can be further tested under different suitable conditions and improves the efficiency of the product.

μ-Coriolis Mass Flow Sensor With Differential Capacitive Readout

In this paper we present a $\mu $ -Coriolis mass flow sensor with differential capacitive readout, which can reduce the effect of common mode vibrations caused by external disturbances. The device consists of two silicon nitride micro-channel loops mechanically connected through two membranes. The sensor is actuated using Lorentz forces, inducing rotation of the sensor’s micro-channels. Coriolis forces of opposite sign are subsequently generated in the two channel loops. Thus, any common mode vibration can be distinguished from vibration induced by mass flow through the channels. Capacitive readout structures surround the sensor to detect these vibrations. A piezo-electric resonator is placed in close proximity to the sensor to generate artificial external disturbance. Flow measurements are executed to compare the differential readout method to a single ended readout with and without external disturbances. The flow sensitivity is unaffected. However, the mean deviation of the output signal is 60-70% lower when using the differential readout compared to single ended readout when external disturbances are induced. The effect of external disturbances on the zero flow stability is reduced by approximately 64% by using the differential readout. Full elimination of the effect is not possible due to non-linearity of the readout capacitors. Reducing non-linearity of the readout could further improve performance, e.g. by implementing (piezo-resistive) strain gauges on top of the micro-channel.

Simulation of Ti-Twin S - Shape Vibration Based Mass Flow Sensor

This paper contains in modelling of twin S-shape coriolis mass flow sensor in Titanium tube and then performing the simulation to determine the optimum phase-shift. To measure the mass flow rate coriolis mass flow sensor is placed inside the tube. The phase shift appears due to the twist in the structure as a result of interactions between the vibration and fluid flow. The phase shift calculated at different sensor positions is helpful in calibrating the accurate mass flow rate and to the optimal sensor position. The coriolis mass flow sensor is modelled in CATIA V5 and simulation is performed in ANSYS 16.2. tube material is titanium and working fluid is water.

μ-Coriolis Mass Flow Sensor with Resistive Readout.

This paper presents a -Coriolis mass flow sensor with resistive readout. Instead of measuring a net displacement such as in a capacitive readout, a resistive readout detects the deformation of the suspended micro-fluidic channel. It allows for actuation at much higher amplitudes than for a capacitive readout, resulting in correspondingly larger Coriolis forces in response to fluid flow. A resistive readout can be operated in two actuation vibrational modes. A capacitive readout can only be operated in one of these two modes, which is more sensitive to external disturbances. Three types of devices have been realized. We present measurement results for all three devices. One device clearly outperforms the other two, with a flow sensitivity of 2.22 °/(g·h−1) and a zero-flow stability of 0.02 g·h−1 over 30 min. Optimization of the metal strain gauges and/or implementation of poly-Silicon strain gauges could further improve performance.

Simulation of S Shape Coriolis Mass Flow Sensor

The paper intent in modelling of S-shape coriolis mass flow sensor and then per-forming the simulation for determining the desired phase-shift. The coriolis mass flow sensor is a device that measures mass flow rate of a fluid inside the tube. It is also known as inertia flow meter. The phase shift appears due to the twist in the structure as a result of interactions between the vibration and fluid flow. The phase shift calculated at different sensor positions is helpful in calibrating the ac-curate mass flow rate and to ascertain the optimal sensor position. The coriolis mass flow sensor is modelled in CATIA V5 and simulation is performed in ANSYS 16.2. Tube material is copper and working fluid is water.

Design and Simulation of Disposable S Shape Coriolis Mass Flow Sensor using FEA Method

The aim of this paper is to design and evaluate natural frequency of disposable S shape coriolis mass flow sensor (CMFS). Three disposable materials used for performing modal analysis are PVDF (polyvinylidene fluoride), PP (polypropylene) and PEEK(polyether ether ketone). The design of coriolis mass flow sensor (CMFS) is done in CATIA V5 and simulation is performed in ANSYS 16.2. Simulation is performed by considering fluid inside the tube. Water is used as working fluid.

Optimisation of sensor position for maximum phase shift OF CU TWIN-S shape CMFS

Modeling and simulation of twin S-shape Coriolis mass flow sensor (CMFS) for copper twin tube has been done in which phase shift is optimized. The CMFS works on the Coriolis principle in which copper tube is fitted inside the sensor. Due to vibration of tube at natural frequency, the phase shift is observed during fluid flow. Phase shift is calculated at various sensor locations and the optimized positions are being identified. Phase shift are helpful in calibrating the accurate mass flow rate and to find the optimal sensor position. Simulation is performed using ANSYS 16.2 on a model of CMFS which is modeled in CATIA V5. During this study tube material is copper and working fluid is selected as water.

Flow through calorimeter to measure fluid heat capacity in CSP applications

Performance tests of concentrating solar collectors are based on energy balance studies which require accurate measurements of fluid mass flow rate, temperature difference over the collector length and the knowledge of the specific heat capacity of the used heat transfer fluid (HTF). Especially at operation temperatures in the range of 200–400 °C, the accuracy of HTF manufacturer data regarding the specific heat capacity of used HTFs is insufficient. This shortcoming contributes significantly to the overall measurement uncertainty of thermal collector assessments. In the present paper, the measurement results of a flow through calorimeter measuring the specific heat capacity of SYLTHERM 800 under field conditions at temperatures up to 330 °C are presented. The HTF measurement shows good agreement (deviation below 1.2%) with a Differential Scanning Calorimetry (DSC) measurement for temperatures below 270 °C. For higher temperatures, the deviation between flow through calorimeter and DSC measurement increases to 3.7% at 330 °C. Furthermore, several technical design and measurement improvements over the calorimeter design presented in 2012 are described in detail. A validation measurement using water reveals deviations below 0.1% from the water reference values at ambient temperatures. A stringent uncertainty analysis reveals the largest individual measurement uncertainty. The unexpectedly large uncertainty of the Coriolis mass flow sensors at temperatures above 270 °C is distinguished by a large individual uncertainty and the comparison to DSC.

Omega Design and FEA Based Coriolis Mass Flow Sensor (CMFS) Analysis Using Titanium Material

The main highlight of this research work is evaluation of resonant frequency for titanium omega type coriolis mass flow sensor. Coriolis mass flow sensor is used for measuring direct mass flow in pipe useful for various industrial applications. It works on the principle of Coriolis effect. Finite Element Analysis (FEA) simulation of omega flow sensor was performed using Ansys 14.5 and Solid Edge, Pro-E was used for modelling of omega tube. Titanium was selected as omega tube material. Experimental setup was prepared for omega tube coriolis flow sensor for performing different test. Experimental setup was used for investigation of different parameters effect on CMFS and validation of simulation results.

Experimental analysis of thermomechanical noise in micro Coriolis mass flow sensors

Coriolis mass flow sensors mechanically detect mass flows using a vibrating channel. For microfabricated sensors, thermomechanical noise causes random vibrations and defines therefore a fundamental limit to the resolution of the sensor. This is modeled using the equipartition theorem. In an experimental setup, the displacement of the channel due to thermomechanical noise is measured using a laser Doppler vibrometer for temperatures between approximately 300 K and 700 K. The results show RMS vibration amplitudes of 38 pm to 57 pm for a bandwidth of 13 Hz, as predicted by the model. This corresponds to a noise equivalent mass flow of 0.3 ng s−1. It is shown that the resolution of the currently most sensitive Coriolis mass sensor is still one to two orders of magnitude above the thermal noise limit.

Integrated Pressure Sensing Using Capacitive Coriolis Mass Flow Sensors

The cross-sectional shape of microchannels is, dependent on the fabrication method, never perfectly circular. Consequently, the channels deform with the pressure, which is a non-ideal effect in flow sensors, but may be used for pressure sensing. Multiple suspended channels with different lengths were modeled, fabricated, and characterized to verify the use and the scalability of this effect for pressure sensing. Furthermore, it is shown that the pressure dependence can be distinguished from the Coriolis effect in microfabricated Coriolis mass flow sensors, enabling the measurement of the pressure next to flow and density with only the flow sensor itself. In addition, this allows for further improvement in the accuracy of the flow measurement by correcting for the small pressure dependence.

SU–8 micro coriolis mass flow sensor

This work presents the modelling, design, fabrication and test of the first micro Coriolis mass flow sensor fully fabricated in SU-8 by photolithography processes. The sensor consists of a channel with rectangular cross-section with inner opening of 100μm×100μm and is actuated at resonance by Lorentz forces. Metal tracks for the actuation current are deposited on top of the chip. The chip has been tested over a flow range of 0–800mg/min in the case of water and 0–650mg/min for isopropyl alcohol (IPA) to confirm that the sensor measures true mass flow (at the maximum flow of the tested range, 0–800μl/min for both water and IPA, it results in a pressure drop of 0.98bar for water and 1.97bar for IPA).

Mathematical model of time difference for Coriolis flow sensor output signals under gas-liquid two-phase flow

Abstract The features of Coriolis mass flow sensor output signal are analyzed, and a mathematical model of the time difference for the signals is built to evaluate the rationality and limitation of the proposed correction method when Coriolis mass flowmeter (CMF) is used to measure the gas-liquid two-phase flow. According to the experimental data of Coriolis mass flow sensor output signals under the gas-liquid two-phase flow condition, the time differences of the sensor output signals are extracted as a characteristic quantity to obtain the time difference sequence by adopting a digital zero-crossing detection method. The distribution pattern of the time difference sequence is analyzed with the probability density function, and the mathematical model of the time difference sequence is built by the correlation analysis. The mathematical model consists of a stable component and a fluctuating component. Correcting the stable component can improve the measurement accuracy of cumulative mass flow rate, and reducing the fluctuating component can enhance the measurement stability of instantaneous mass flow rate. Although the stable component cannot be completely corrected because its variation is nonlinear with the flow rate and drop in density, and the fluctuating component can only be reduced to a certain extent due to the real-time processing limitation of the instrument, CMF can provide relatively reliable measurement results of the liquid mass flow rate when the gas-liquid two-phase flow occurs.

Uncertainty analysis for design and optimization of a micro Coriolis mass flow sensor

The purpose of this paper’s theoretical study is to evaluate the relative influence of structure parameters on the inherent frequency and sensitivity of the micro Coriolis mass flow sensor. Structure parameters of the micro flow sensor play an important role in applications of accurate measurements. But these are not precisely obtained due to the manufacturing error. In this paper, the inherent frequency and sensitivity of the micro Coriolis mass flow sensor driven by non-contact capacitance excitation are established, respectively. The sample-based stochastic model is established considering uncertainty distributions of structure parameters. The relative influences are revealed by the results of simulation experiments and the key influence parameters are obtained. The results could be useful, not only for giving a clearer understanding of the sensor’s behavior, but also as a guideline for its design and optimization.

Theoretical analysis and experimental study of Coriolis mass flow sensor sensitivity

The measuring tube is the core sensitive unit of the Coriolis mass flow sensor. Its design parameters directly influence natural frequency and sensitivity, such as shape and structure dimensions. In this study, we obtained under concentrated force the equivalent elastic coefficient of the measuring tube by adopting static analysis and calculating static deflection curves, including the respective U-shape, slightly curved, and straight tubes. We then obtained the resonant frequency from the second-order vibration equation. Additionally, the maximum sensitivity and position coordinates were obtained by calculating the torsional displacement curve of the measuring tube under the distribution of Coriolis force during a rated flow. Sensor models with different measuring tube shapes were designed by applying this theoretical analysis. Calibration tests for sensors were performed using a static gravimetric method. Theoretical analysis and test results show that the resonant frequency and sensitivity of the sensors calculated by applying static mechanical analysis and Coriolis distributing force align with the experimental results, thereby proving the validity of the theoretical method. Furthermore, the proposed method simultaneously obtained the relation curve of the measuring tube structure dimensions and natural frequency and sensitivity. It therefore provides theoretical evidence for the sensor design and detector installation position.