Shangchun Fan

Beihang University (BUAA) | BUAA

Micro/nano waveguide has been widely exploited for gas sensing due to its strong confinement of evanescent field, compact size, and fast response. However, the state-or-the-art evanescent-wave gas sensors still struggle to satisfy the requirements of high sensitivity, high selectivity, large dynamic range, and long-term stability. In this work, mic...

The temperature influence is one of the main factors affecting the accuracy improvement of the MEMS resonant sensor. For the electrothermally excited MEMS resonant sensor, temperature influence not only comes from the inherent thermal temperature rise, but also depends on the change of ambient temperature. However, due to the complex structure, dif...

We demonstrate a high sensitivity all-fiber spectroscopic methane sensor based on photothermal interferometry. With a 2.4-m-long anti-resonant hollow-core fiber, a 1654 nm distributed feedback laser, and a Raman fiber amplifier, a noise-equivalent concentration of ${\sim}{4.3}\;{\rm ppb}$ ∼ 4.3 p p b methane is achieved at the room temperature and...

We report mode-phase-difference photothermal spectroscopy with a dual-mode anti-resonant hollow-core fiber. Ultra-sensitive gas detection down to ppt level is demonstrated with good stability and unprecedented dynamic range of over 7 orders of magnitude.

The characteristic of weak resonant signal output by an electrothermally excited microresonator is analyzed, and the principal component analysis (PCA) method is proposed and applied in the resonant frequency detection of the output weak signal by separating the noises. Simulation on weak resonant signals under different levels of noises and differ...

In this paper, we demonstrate a miniature flexible FBG-based underwater ultrasonic sensor with enhanced pressure sensitivity and bandwidth using a side-polished configuration of ~54 μm depth and ~15 mm length. The opto-mechanical responses of the sensor to acoustic-induced strain in axial and radial receiving modes are investigated and characterize...

We demonstrate here an ultrafast, miniature, and high-performance fiber-tip Fabry–Perot (F-P) humidity sensor with ∼ 300 nm -thick graphene oxide (GO) diaphragm suspended onto the end face of a capillary tube with an inner diameter of 50 μm and a cavity length of ∼ 100 μm . The sensitivity to relative humidity (RH) spanning from ∼ 10 % RH to ∼ 90 %...

For the difficulty in evaluating the flow stability of flow standard facility, a measuring method base on the relationship analysis of flow rate and pressure is presented. It can obtain the amplitude and frequency of flow fluctuation in a wide frequency range, and overcome the fluctuation amplitude distortion caused by the insufficient sampling fre...

Impulse pressure generator with dropped mass is commonly used for dynamic pressure calibration, but there is always high frequency oscillation in the rising edge of the pressure waveform especially for the low amplitude impulse pressure. Through the dynamic analysis and modeling of the whole process of the impulse pressure generator based nonlinear...

The relationship between flow fluctuation and pressure in a flow facility is studied theoretically and experimentally in this paper, and a method for measuring the flow fluctuation is proposed. According to the synchronicity of pressure and flow fluctuation, the amplitude of the flow fluctuation is calculated using the pressure measured in the flow...

Boundary structure and geometry parameters of the Double-Ended-Tuning Fork (DETF) resonator in a micro-accelerometer are investigated. The theoretical vibration model of a DETF resonator is established and verified by the simulation results obtained by finite element method. Uncertainty analysis incorporating the parametric uncertainty distribution...

We developed a novel open-cavity Fabry-Perot (F-P) interferometer with multilayer graphene diaphragm suspended on the endface of a ferrule. The insensitivity to relative-humidity (RH) ranging from ~20 %RH to 70 %RH was investigated in terms of the wavelength shift and power change in interference spectrum, along with the balanced air pressure on bo...

Uncertainty method incorporating the parametric uncertainty distribution is used to systematically investigate the influence of different slit sizes and excitation parameters on performance of double-clamped resonant beam with slit structure in a MEMS resonant pressure sensor, when inherent heat elevation of electro-thermal excitation is taken into...

A miniature flexible fiber Bragg grating (FBG) acoustic sensor with enhanced pressure sensitivity was fabricated by using a side-polished configuration of ∼54 μm depth and ∼15 mm length. The photoelectromechanical response of the sensor suspended as a dual-end-fixed beam was characterized based on the acoustic-induced strain interaction with fiber...

We demonstrated a miniature and in situ ~13-layer graphene nanomechanical resonator by utilizing a simple optical fiber Fabry-Perot (F-P) interferometric excitation and detection scheme. The graphene film was transferred onto the endface of a ferrule with a 125-μm inner diameter. In contrast to the pre-tension induced in membrane that increased qua...

We proposed a novel miniature liquid marble-based room-temperature optical fiber tilt sensor by using Fabry-Perot (F-P) interferometric detection, with the advantages of simple fabrication, wide range, good linearity, and low cost, aside from the immunity to electromagnetic interference. A mercury marble with a diameter of 1.3 mm and a length of 10...

Structure parameters of Coriolis mass flowmeter play an important role in both the theory and practical applications of accurate measurements. They are not precisely known due to the manufacturing error, but the values thereof lie within the allowed range. This paper is mainly focussed on evaluating the relative impact of structure parameters on pe...

This paper proposed a kind of real-time online solving method based on the analog circuit for the output signal solution of frequency resonant gyroscope. This method firstly established the vibration differential equation of frequency resonant gyroscope, deduced the output signal solving model under some constraints, and used the digital simulation...

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 m...

Vibration model of double-clamped resonant beam for a MEMS resonant sensor driven by electro-thermal excitation is established. Thermal phase drift caused by electro-thermal excitation and output frequency error of phase locked loop (PLL) caused by thermal phase shift are analyzed. The effects of uncertainty distributions of structure size and exci...

Thickness measurement plays an important role for characterizing optomechanical behaviors of graphene. From the view of graphene-based Fabry–Perot (F–P) sensors, a simple, nondestructive and in situ method of determining the thickness of nanothick graphene membranes was demonstrated by using optical fiber F–P interference. Few-layer/multilayer grap...

Waals adhesion behavior at the interface between graphene and support substrates is important to characterize the performance of graphene-based sensors. Here an improved, general, and direct method of determining the adhesion energies of monolayer/few-layer/multilayer graphene sheets on silicon wafers is demonstrated by measuring the debonding radi...

A new method with laser interferometry is used to enhance the traceability for sinusoidal pressure calibration in water. The laser vibrometer measures the dynamic pressure based on the acousto-optic effect. The relation of the refractive index of water and the optical path length with the pressure’s change is built based on the Lorentz–Lorenz equat...

This paper presents the architecture and optimization verification of a designed mode-mismatching gyroscope prototype made with fused silica in atmospheric pressure. The gyroscope prototype uses the decoupling frame and double-ended tuning fork (DETF) to achieve high sensitivity and quality factor. This structure can suppress residual quadrature er...

We demonstrated a multilayer molybdenum disulfide (MoS2) nanomechanical resonator by using optical Fabry-Perot (F-P) interferometric excitation and detection. The thin circular MoS2 nanomembrane with an approximate 8-nm thickness was transferred onto the endface of a ferrule with an inner diameter of 125 μm, which created a low finesse F-P interfer...

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 s...

Application of the Fabry-Perot (FP) interference method for determining the coefficient of thermal expansion (CTE) of a graphene diaphragm is investigated in this paper. A miniature extrinsic FP interferometric (EFPI) sensor was fabricated by using an approximate 8-layer graphene diaphragm. The extremely thin diaphragm was transferred onto the endf...

Van der Waals adhesion between graphene and substrate has an important impact on the graphene-based sensor performance. Here, we proposed a simple in situ measurement method for the adhesion energy of the graphene diaphragm suspended on the endface of a ferrule. The interaction between the diaphragm and its substrate created a low finesse Fabry-Per...

Due to higher mechanical strength and ultra-thin thickness, graphene is used as a sensitive diaphragm in a Fabry–Perot cavity to improve the sensitivity of pressure sensors. In accordance with the working principle of Fabry–Perot interferometer, a load–deflection mathematical model of fiber-tip pressure sensor with graphene membrane is established...

The Modbus/TCP protocol cannot guarantee the real-time capability. A token ring scheduling algorithm that featured by priority to provide the real-time response to the Modbus/TCP messages is designed. The average response delay on a μC/OS-II + ARM7 platform is 1.117 ms, which is better than most average response delay reported in current researches...

A miniature Fabry-Perot interferometric sensor with an ultra-high temperature sensitivity was constructed by using an approximate 8-layer graphene diaphragm. The extremely thin diaphragm was transferred onto the endface of a ferrule with an inner diameter of 125 μm, and van der Waals interactions between the graphene diaphragm and its substrate cre...

A new maglev sensor is proposed to measure ultra-low frequency (ULF) vibration, which uses hybrid-magnet levitation structure with electromagnets and permanent magnets as the supporting component, rather than the conventional spring structure of magnetoelectric vibration sensor. Since the lower measurement limit needs to be reduced, the equivalent...

This paper proposes one study method of resonant MEMS gyroscope based on the circuit in order to solve problems such as long verification cycle and high cost of the MEMS gyroscope structure design. Firstly, on the basis of Euler–Bernoulli beam theory, this study establishes resonant beam vibration equation, obtains semi-Mathieu equation after norma...

A miniature Fabry–Perot interferometric acoustic sensor with an ultra-high pressure sensitivity was constructed by using approximately 13 layers of graphene film as the diaphragm. The extremely thin diaphragm was transferred onto the endface of a ferrule, which had an inner diameter of 125 μm, and van der Waals interactions between the graphene dia...

Considering the potential application of graphene in optical fibre Fabry-Perot pressure-sensitive membrane, a constitutive model for strain-induced deformation characteristics of graphene membrane was established based on the large deflection elastic theory of circular membrane. The effects of membrane parameters, including pre-stressing force, You...

The Micro-Electro-Mechanical System Coriolis mass flow sensor uses a kind of in-plane comb-shaped capacitor to detect the vibration of tube containing the micro flow information. This paper takes the deflection of the micro tube caused by Coriolis force into account and models the in-plane comb-shaped capacitor of the sensor based on the electrosta...

In this paper, the application of weak signal detection based on chaotic oscillator is studied in a MEMS resonant beam sensor. Chaotic oscillator can detect weak signal which is submerged in the background of large noise. According to the frequency and phase characteristic of the output vibrating signal, reference current signal with fixed frequenc...

Detection method of colloidal gold immunochromatography assay concentration using colorimetric principle, when tested in liquid reagent on antigen and antibody response, reagent detection area change color, and compared to standard color grade then the concentration can be qualitative analysis. At present, the concentration of colloidal gold test s...

In the oil industry, the accompanied reverberation is a major constraint in the transmission rate and distance because the drillstring is a heterogeneous assembly. Based on the transient impulse responses in uplink and downlink channels, an improved simplified echo suppression model with two acoustic receivers is presented in consideration of posit...

A new device is built to measure the mechanical characters of the double ended tuning fork which is used as the sensitive element of resonant sensor. It is mainly composed of a three dimensional workbench, a force sensor, a servo motor, control circuit and a photodiode. Detailed theoretical analysis is carried out to verify the feasibility of the d...

In this paper, we established the vibration model of double-clamped resonant beam with slit structure, and we theoretically analyzed the effect of rectangular slits with round corners on vibration amplitude and natural frequency of the resonant beam. The effect of rectangular slits on detection sensitivity of resonant beam is also analyzed. Accordi...

A new method of wireless data telemetry used by oil industry uses compressional acoustic waves to transmit downhole information from the bottom hole to the surface. Unfortunately, acoustic echoes and drilling vibration noises in periodic drillstring are a major issue in transmission performance. A combined acoustic echo and noise suppression method...

A vibration model of double-clamped resonant beam that is driven by electro-thermal excitation for a MEMS resonant sensor is established. The sample-based stochastic model is established to investigate the influence of different uncertain structure size and excitation parameters on sensor performance. Effects of uncertainty distributions of structu...

Closed-loop control system undertakes the foundational task of maintaining the permanent vibration of the measuring tube for Coriolis Mass Flowmeter (CMF). In order to overcome the disadvantages of bad anti-jamming, slow response speed and high zero drift existing in conventional analog closed-loop system, a novel digital closed-loop control system...

As a resonate sensor, Coriolis Mass Flowmeter (CMF) provides a direct measurement of mass flow and is widely used in flow measurement field. However, defect of dynamic characteristics has become the main factor which restricts its further application in batch filling processes. Based on theoretical analysis, a dynamic compensation system, BP (Back-...

A fiber-optic Fabry-Pérot acoustic sensor with a ~100-nm-thick multilayer graphene diaphragm is reported. Acoustic testing demonstrates a pressure-induced deflection of 1100 nm/kPa and a noise equivalent acoustic signal level of ~ 60 μPa/Hz1/2 at the frequency of 10 kHz. The sensor exhibits a flat frequency response from 0.2 to 22 kHz and may be us...

In this paper, Mathieu equation is applied to analyze the dynamic characteristics of resonant inertial sensors. Unlike previous work, Mathieu equation is not just a differential equation and analyzes the stability of the transition curves, but become an important method in analyzing parametric resonant characteristics and approximate output of reso...

A pipeline network security warning system is designed based on vibration detection techniques, which consist of the front nodes module, relay modules and the computer monitor center in this paper. Someone dig in the ground of pipeline and destruction of the pipeline, when pipe stress change and the acceleration sensor close to the walls of the pip...

The micro-vibration of satellite is a key factor which affects the major performance of high precision camera. At the same time, it limits the improvement of the camera resolution, and it impacts the efficiency in resource exploration and emergency treatment of serious natural disasters. This paper starts with the vibrating environment of the satel...

There is evidence to suggest that microgravity/weightlessness can induce changes in lung physiology/function. We hypothesized that microgravity, induced by head-down bed rest (HDBR), would induce changes in lung function and that exercise training with artificial gravity (AG) would prevent these changes from occurring. Twelve participants were rand...

Graphene has remarkable mechanical properties, and it is a very promising material for sensors. The progress of graphene diaphragm based pressure sensor was detailed firstly. Then the deflection of pressurized circular graphene diaphragm with pre-stress was discussed, an approximate solution was given to substitute Hencky’s series solution. Pre-str...

We report a principle prototype of space animal cell perfusion culture and observation. Unlike previous work, our cell culture system cannot only realize microfluidic and temperature controlling, automatic observation, and recording but also meet an increasing cell culture at large scale operation and overcome shear force for animal cells. A key co...

In order to increase the accuracy of on-line liquid density measurements, a sensor equipped with a tuning fork as the resonant sensitive component is designed in this paper. It is a quasi-digital sensor with simple structure and high precision. The sensor is based on resonance theory and composed of a sensitive unit and a closed-loop control unit,...

Non-linear dynamics of a resonant silicon bridge pressure sensor with electrothermal excitation has been investigated. Non-linear vibration model of the bridge resonator in the pressure sensor is developed by Euler–Bernoulli beam modeling. Besides non-linear geometric effect, the model also takes into account the measured pressure, the heating effe...

In this paper, frequency measurement methods of resonant vibratory gyroscopes are studied. First, the working principle and dynamic output characteristics of the resonant vibratory gyroscope are introduced, which provide a theoretical analysis base to analyze the dynamic frequency output characteristic of the resonant vibratory gyroscope. Moreover,...

Main stress types that affect the service life of cylinder were obtained through analysis of cylinder failure mechanism, including environmental temperature for cylinder operation, actuation velocity, positive pressure of load and gas pressure, a life-stress model for cylinder was built based on tribology theory, and the physical measurement unit f...

This paper proposes a slit-resonant beam based on the double clamped resonant beam theory of silicon micro-machined resonant pressure sensors. The slit structure can enhance surface alternating stress in the root area of beam while vibrating. Finite element method (FEM) is applied to calculate the stress concentration magnification, and we carry ou...

The Coriolis mass flow meter, for its features of directly measuring mass flow and high precision, is widely utilized in the flow measuring fields like batch filling and commercial trade. However, the unsatisfactory dynamic performance is one major constraint to Coriolis mass flow meter from being even more widely used in batch filling industry. To...

A novel micro resonant accelerometer was designed for increasing the sensitivity of resonant accelerometer, which includes two double-ended tuning forks, a proof mass, two-leverage system amplifying inertial force, and drive/sense combs. Each tuning fork is electro-statically actuated and sensed at resonance using comb electrodes. The device is fab...

In this paper, a digital demodulation method used for AC-based electrical tomography systems is presented. The demodulation result can be easily obtained by rectifying the sinusoidal measurement signal in a digital way. The proposed demodulation method has some distinguished characteristics: (a) with a concise configuration, it can be implemented o...

In the capacitive rotary position sensor, noise jamming generated by the motor is mixed in the response signal, so it is difficult to measure precisely. This paper presents an IIR filter solution with cascade structure. An IIR band-pass filter of 8-order is designed by Matlab, and then be disintegrated into 4 sub-filters. The band-pass frequency of...

Coriolis mass flow sensor tends to be straight tube and micro bending tube with higher noise rejecting and less pressure loss, which results in the increase of the operating frequency, the difficulty in detecting phase difference and the calculation accuracy. Based on the current method of amplitude ratio calculation, the paper analyzes how the Cor...

A variable permittivity capacitance measuring method is proposed in this paper for solid wood plate defects detection. A fast and non-contact NDT is realized by measuring the difference of capacitances between the plates with and without defects. Theoretical and simulation analysis are firstly presented to validate this method, then two wood sample...

Cell culture and observation is the essential link of space use and development from biological engineering direction, especially is research key steps of space medicine research from a cellular and molecular level. In order to develop space cell biology, it must have corresponding hardware equipment, namely cell culture and cell observation device...

This paper studied the stress concentration effect of silt structure on the resonant beam, and proposed a slit-resonant beam based on the double clamped resonant beam theory of silicon micro-machined resonant pressure sensor. The stress concentration effect can enhance surface alternating stress in the root area of beam when resonant beam is vibrat...

In order to make the operation of stereo microscope more convenient and acquisition high quality images, we develop a novel motorized stereo microscpe and propose new auto-focusing (AF) algorithm. X, Y and Z (focus) axis positions of the microscopic stage are visual feedback controlled to focus. The focus evaluation function based on the morphologi...

Dynamic characteristics of resonators for MEMS resonant vibratory gyroscopes are studied in this paper. Firstly, a small parameter method is introduced to analyze the dynamic characteristic stability of the resonator. It is proved that geometrical parameters of the resonator have to be regulated to match corresponding stability analysis. In order t...

To restrain the zero drift of a piezoelectric accelerometer and the zero drift from a charge amplifier (CA) in an ultrahigh-g impact environment, a reformative design approach for an on-board ultrahigh-g deceleration–time measurement system is presented. First, a simplified zero-drift model of the on-board ultrahigh-g deceleration–time measurement...

To reduce measurement time of micro-machined resonator and improve measurement efficiency, a novel frequency character measurement method for micro-machined resonator based on piezoresistive detection is put forward. An Ohm phase sensitive detector (Ohm-PSD), an integrator and MCU are used to achieve the effective detection of weak signal. The phas...

A method is introduced to measure the micro-capacitance for MEMS comb actuators whose value is in pF even fF magnitude. This method uses so called peak detection measuring technology to realize this purpose. It is mainly composed of the signal generating circuits, C/V (Capacitance/Voltage) converting part, peak detector circuits and the digital sol...

The current development trends of international higher engineering education and related disadvantages in China are described. According to the medium and long-term educational reform and development program as well as outstanding engineer training program, an integrated construction of engineering skills and academic literacies is implemented. Its...

An electrothermally excited dual beams silicon resonant pressure sensor with temperature compensation is proposed in this paper. One beam locates upon the diaphragm, whose resonant frequency changes with the measured pressure; the other beam is on the fixed edge, isolated from the pressure effect but sensitive to the temperature variation. Taking t...

Nonlinear dynamics of a resonant silicon bridge pressure sensor with resistive heating excitation has been investigated. Nonlinear vibration model of the microbridge resonator in the sensor is developed by Euler-Bernoulli beam modeling. Besides nonlinear geometric effect, the model also takes the measured pressure, the heating effect of the resisti...

This paper researches on the dynamic performance of a kind of commercial resonant vibration cylinder pressure transducers. The problem of its poor dynamic performance is dealt with by two different approaches. Firstly, in our previous work, it has been justified theoretically by analyzing the structure of this kind of transducers that the effect of...

The resonator simulator provides a new method for researching the resonant sensor closed-loop circuit. In this paper, the mathematic model of silicon pressure resonator is established to design the circuit with resonator characteristic. Firstly the relation between pressure and the amplitude-frequency characteristic of the resonant beam is deduced....

To meet demands for low power and low distortion of micromachined resonant sensor, this paper presents a method to improve present direct digital synthesizer ( DDS ) technology, replacing current zero order holding approximation method to polyline approximation method to reduce the distortion. A theoretical formula in timedomain was calculated, des...

This paper introduces a new theoretical model of plate capacitor for MEMS comb actuator. In this model, bulk fabrication process and edge effect are both considered using integration method and conformal transformation theory. In order to verify the correctness of the model, FEM software is used to calculate the value of the capacitance of the MEMS...

In recent years, the watershed line has emerged as a primary tool of mathematical morphology for image segmentation, though the application of watershed algorithms to an image is often disappointing. Based on the mathematical morphology, this paper develops a general purpose watershed segmentation algorithm used for the automatic segmentation in re...

The process of cell culture in space is very important, but nowadays, advanced space cell culture with imaging system is absent. To develop a new space microscope imaging system, the first thing for us is to analyze the space factors work on the system. So, in this paper, how the main space environment affect imaging system is presented. Firstly, t...

To implement the direct checked of the resonant silicon microstructure sensor integrated testing instrument,and optimize the reactive controlling circuit of resonant sensor, a circuit with resonator Characteristics was designed,the resontor is detected piezoresistively. The Characteristics of piezoresistively,which is the crux of the circuit,was ac...

Microfluidic platforms are microfabricated tools that are gaining popularity for studying of cellular biology. These platforms can allow precise control of the environment surrounding individual cells and have achieved amazing progress in application to cell culture in recent several years. After a brief description of the background and the major...

Coriolis mass flowmeter (CMF) is becoming a research hotspot in flow measurement for its high accuracy and multi-parameter measurement. The detection principle of CMF is to calculate the phase difference of two sine signals which have same frequency. Discrete forurier transform (DFT) and digital correlation are applied in the signal processing of C...

Coriolis Mass Flowmeter(CMF) provides direct measurement of mass flow and is widely used in steady flow measurement. With the development of dynamic flow measurement technology and the increasing of application requirement, the question about dynamic response of CMF has become a hotspot. Recently a lot of research work has been done on this issue a...

Coriolis mass flowmeter (CMF) is significant in many industrial and commercial areas. The two-phase flow, external vibration or flow pulsation in a Coriolis mass flowmeter can cause errors in the meter's measurements of density and mass flow rate. Some errors may be due to the closed-loop control system. In this paper, they are investigated from an...

Coriolis mass flowmeter (CMF) measures the mass flow of fluid by taking advantage of the coriolis force effect resulted from the resonant vibration of measurement tubes. The mechanical coupling vibration of sensor is commonly seen during the actual working process of CMF, which has direct influences to the stability and the measuring accuracy of th...

Application of blind signal processing technique on gas-liquid two-phase flowrate measurement is presented in this paper. Because flowrate is related to the differential pressure (DP) signal which is adopted near the pipe wall when the fluid is flowing along the pipeline, one of flowrate measurement methods is to determine the DP signal correspondi...

The vibration of a general plane tube with a flowing fluid, which is the measuring element in a Coriolis mass flow meter (CMF), is studied. The dynamic stiffness matrix method is used to model such a tube. The tube is divided into straight and circular elements. The elements dynamic stiffness matrices are derived from the equations of motion. By as...

Machine learning and Genetic Algorithm based void fraction measurement method is provided in this paper. Because there are some relationships between the void fraction and the differential pressure (DP) signal acquired near the pipe wall when the two phases are flowing along the pipeline, it is possible to measure the void fraction according to the...

Coriolis mass flowmeter (CMF) is becoming a research hotspot in flow measurement for its high accuracy and multi-parameter measurement. Through the dynamic study on CMF’s vibrating model, get the conclusion that the key factors of close-loop system design is the open-loop characteristic parameters such as natural frequency and mechanical quality fa...

This paper presents the finite element (FE) model of elastic tube containing fluid flow, and simulation calculations are finished for different tubes including straight tube, 1/4 circular one and half circular one. Some conclusions which have instructional significance for designing sensing structure of resonant direct mass flowmeter are obtained....

This paper describes the design, fabrication and test of a silicon micromachined resonant pressure sensor. A square membrane and a doubly clamped resonant beam constitute a compound structure. The former senses the pressure directly, while the latter changes its resonant frequency according to deformation of the membrane. The final output relation...

Microfluidic platforms are microfabricated tools that are gaining popularity for studying of cellular biology. These platforms can allow precise control of the environment surrounding individual cells and have achieved amazing progress in application to cell culture in recent years. In this paper, we discuss the major characteristics of microfluidi...