scholarly journals Ultrafine Aerosol Particle Sizer Based on Piezoresistive Microcantilever Resonators with Integrated Air-Flow Channel

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3731
Author(s):  
Maik Bertke ◽  
Ina Kirsch ◽  
Erik Uhde ◽  
Erwin Peiner
Keyword(s):  
Mass Concentration ◽  
Limit Of Detection ◽  
A Priori ◽  
Micro Electro Mechanical System ◽  
Single Chip ◽  
Air Stream ◽  
Mems Technology ◽  
Clean Air ◽  
Particle Sizer ◽  
Ultrafine Aerosol

To monitor airborne nano-sized particles (NPs), a single-chip differential mobility particle sizer (DMPS) based on resonant micro cantilevers in defined micro-fluidic channels (µFCs) is introduced. A size bin of the positive-charged fraction of particles herein is separated from the air stream by aligning their trajectories onto the cantilever under the action of a perpendicular electrostatic field of variable strength. We use previously described µFCs and piezoresistive micro cantilevers (PMCs) of 16 ng mass fabricated using micro electro mechanical system (MEMS) technology, which offer a limit of detection of captured particle mass of 0.26 pg and a minimum detectable particulate mass concentration in air of 0.75 µg/m3. Mobility sizing in 4 bins of a nebulized carbon aerosol NPs is demonstrated based on finite element modelling (FEM) combined with a-priori knowledge of particle charge state. Good agreement of better than 14% of mass concentration is observed in a chamber test for the novel MEMS-DMPS vs. a simultaneously operated standard fast mobility particle sizer (FMPS) as reference instrument. Refreshing of polluted cantilevers is feasible without de-mounting the sensor chip from its package by multiply purging them alternately in acetone steam and clean air.

scholarly journals Microhotplates for Metal Oxide Semiconductor Gas Sensor Applications—Towards the CMOS-MEMS Monolithic Approach

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 557 ◽  
Author(s):  
Haotian Liu ◽  
Li Zhang ◽  
King Li ◽  
Ooi Tan
Keyword(s):  
Metal Oxide ◽  
Gas Sensors ◽  
Complementary Metal Oxide Semiconductor ◽  
Micro Electro Mechanical System ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Single Chip ◽  
Sensor Applications ◽  
Semiconductor Gas Sensor ◽  
Mems Technology

The recent development of the Internet of Things (IoT) in healthcare and indoor air quality monitoring expands the market for miniaturized gas sensors. Metal oxide gas sensors based on microhotplates fabricated with micro-electro-mechanical system (MEMS) technology dominate the market due to their balance in performance and cost. Integrating sensors with signal conditioning circuits on a single chip can significantly reduce the noise and package size. However, the fabrication process of MEMS sensors must be compatible with the complementary metal oxide semiconductor (CMOS) circuits, which imposes restrictions on the materials and design. In this paper, the sensing mechanism, design and operation of these sensors are reviewed, with focuses on the approaches towards performance improvement and CMOS compatibility.

New Hybrid Methodology for the Development of MEMS Multivariable Sensors

2001 ◽  
Author(s):  
Emily J. Pryputniewicz ◽  
John P. Angelosanto ◽  
Gordon C. Brown ◽  
Cosme Furlong ◽  
Ryszard J. Pryputniewicz
Keyword(s):  
Process Control ◽  
Microelectromechanical Systems ◽  
Absolute Pressure ◽  
Single Chip ◽  
Specific Test ◽  
Mems Sensor ◽  
Test Conditions ◽  
Mems Technology ◽  
Functional Operation ◽  
Hybrid Methodology

Abstract Using recent advances in microelectromechanical systems (MEMS) technology, a new multivariable sensor was developed. This MEMS sensor, capable of measuring temperature, absolute pressure, and differential pressure on a single chip, is particularly suitable for applications in process control industry. However, functional operation of the sensor depends on validation of its performance under specific test conditions. We have developed a hybrid methodology, based on analysis and measurements, that allows such validation. In this paper, the MEMS multivariable sensor is described, the hybrid methodology is outlined, and its use is illustrated with representative results.

Thermal Bubble Dynamics Under the Effect of Acoustic Vibration

2009 ◽  
Author(s):  
Xiaopeng Qu ◽  
Huihe Qiu
Keyword(s):  
Heat Transfer ◽  
Acoustic Field ◽  
Vapor Bubble ◽  
Boiling Heat Transfer ◽  
High Speed ◽  
Bubble Dynamics ◽  
Acoustic Vibration ◽  
Micro Electro Mechanical System ◽  
Mems Technology ◽  
Enhanced Boiling

The effect of acoustic field on the dynamics of micro thermal bubble is investigated in this paper. The micro thermal bubbles were generated by a micro heater which was fabricated by standard Micro-Electro-Mechanical-System (MEMS) technology and integrated into a mini chamber. The acoustic field formed in the mini chamber was generated by a piezoelectric plate which was adhered on the top side of the chamber’s wall. The dynamics and related heat transfer induced by the micro heater generated vapor bubble with and without the existing of acoustic field were characterized by a high speed photograph system and a micro temperature sensor. Through the experiments, it was found that in two different conditions, the temperature changing induced by the micro heater generated vapor bubble was significantly different. From the analysis of the high speed photograph results, the acoustic force induced micro thermal bubble movements, such as forcibly removing, collapsing and sweeping, were the main effects of acoustic enhanced boiling heat transfer. The experimental results and theoretical analysis were helpful for understanding of the mechanisms of acoustic enhanced boiling heat transfer and development of novel micro cooling devices.

High Q Circular-Section Solenoid-Type Inductor

2008 ◽  
Author(s):  
Xiuhan Li ◽  
Guanghua Shu ◽  
Jinan Sao ◽  
Xiongwei Zhang
Keyword(s):  
Flip Chip ◽  
Micro Electro Mechanical System ◽  
The Self ◽  
Cmos Process ◽  
Structure Parameters ◽  
Q Factor ◽  
Circular Section ◽  
High Q ◽  
Ansoft Hfss ◽  
Mems Technology

A* high Q-factor circular-section solenoid-type inductor is designed and fabricated through micro electro mechanical system (MEMS) technology. The radius of the circular-section is 100μm. Ansoft HFSS is used to design and optimize the structure parameters of the inductor. The stable inductance of 10nH and maximum Q-factor of 46 is gained at the N of 10, wire width w of 10μm, space between wires d of 15μm and the self-resonance frequency of the inductor is above 10GHz. A novel fabrication method—flip chip bonding is proposed to bond the two parts of the inductor, and the process is compatible with CMOS process.

scholarly journals Partially integrated cantilever-based airborne nanoparticle detector for continuous carbon aerosol mass concentration monitoring

2015 ◽  
Vol 4 (1) ◽  
pp. 111-123 ◽  
Author(s):  
H. S. Wasisto ◽  
S. Merzsch ◽  
E. Uhde ◽  
A. Waag ◽  
E. Peiner
Keyword(s):  
Real Time ◽  
Mass Concentration ◽  
Limit Of Detection ◽  
Time Measurement ◽  
Engineered Nanoparticles ◽  
Direct Reading ◽  
Real Time Measurement ◽  
Aerosol Mass Concentration ◽  
Silicon Cantilever ◽  
Airborne Nanoparticle

Abstract. The performance of a low-cost partially integrated cantilever-based airborne nanoparticle (NP) detector (CANTOR-1) is evaluated in terms of its real-time measurement and robustness. The device is used for direct reading of exposure to airborne carbon engineered nanoparticles (ENPs) in indoor workplaces. As the main components, a miniaturized electrostatic aerosol sampler and a piezoresistive resonant silicon cantilever mass sensor are employed to collect the ENPs from the air stream to the cantilever surfaces and to measure their mass concentration, respectively. Moreover, to realize a real-time measurement, a frequency tracking system based on a phase-locked loop (PLL) is built and integrated into the device. Long-term ENP exposure and a wet ultrasonic cleaning method are demonstrated to estimate the limitation and extend the operating lifetime of the developed device, respectively. By means of the device calibrations performed with a standard ENP monitoring instrument of a fast mobility particle sizer (FMPS, TSI 3091), a measurement precision of ENP mass concentrations of < 55% and a limit of detection (LOD) of < 25 μg m−3 are obtained.

Design and operation of a bio-inspired micropump based on blood-sucking mechanism of mosquitoes

2018 ◽  
Vol 32 (12n13) ◽  
pp. 1840027 ◽  
Author(s):  
Tzong-Shyng Leu ◽  
Ruei-Hung Kao
Keyword(s):  
Taguchi Method ◽  
Power Density ◽  
Flow Rate ◽  
Transient Flow ◽  
Micro Electro Mechanical System ◽  
Experimental Result ◽  
Channel Size ◽  
Lumped Model ◽  
Blood Sucking ◽  
Mems Technology

The study is to develop a novel bionic micropump, mimicking blood-suck mechanism of mosquitos with a similar efficiency of 36%. The micropump is produced by using micro-electro-mechanical system (MEMS) technology, PDMS (polydimethylsiloxane) to fabricate the microchannel, and an actuator membrane made by Fe-PDMS. It employs an Nd-FeB permanent magnet and PZT to actuate the Fe-PDMS membrane for generating flow rate. A lumped model theory and the Taguchi method are used for numerical simulation of pulsating flow in the micropump. Also focused is to change the size of mosquito mouth for identifying the best waveform for the transient flow processes. Based on computational results of channel size and the Taguchi method, an optimization actuation waveform is identified. The maximum pumping flow rate is 23.5 [Formula: see text]L/min and the efficiency is 86%. The power density of micropump is about 8 times of that produced by mosquito’s suction. In addition to using theoretical design of the channel size, also combine with Taguchi method and asymmetric actuation to find the optimization actuation waveform, the experimental result shows the maximum pumping flowrate is 23.5 [Formula: see text]L/min and efficiency is 86%, moreover, the power density of micropump is 8 times higher than mosquito’s.

Industrial Verification of Piezo Motors on a CubeSat Based Verification Platform

2006 ◽  
Author(s):  
Manuel Czech ◽  
Ulrich Walter
Keyword(s):  
Complex Systems ◽  
Low Complexity ◽  
Micro Electro Mechanical System ◽  
Mission Design ◽  
Technology Readiness ◽  
Key Technology ◽  
Mems Technology ◽  
Segmented Mirror ◽  
Mirror Telescope

Due to the classification of technologies in NASA’s and ESA’s technology readiness levels, newly developed components have to be space proven before they can be utilized in space missions. This space prove can be adduced by sending these technologies to orbit either as experiment on a piggyback flight or a dedicated mission. Over the last years the size of technologies and satellites has shifted to much smaller sizes. In this paper, the possibility of industrial verification of MEMS (Micro Electro Mechanical System) applications using dedicated pico-satellite missions is examined. Based on the CubeSat concept, a technology verification platform can be realized for verification of not only pico-satellite components, but also of components of complex systems and missions. Therefore a platform fulfilling the requirements for such industrial verification of components named MOVE (Munich Orbital Verification Experiment) is developed at the Institute of Astronautics (LRT). This platform enables professional verification of MEMS technology and techniques at overall mission costs of less than 100k€. As a first application of this approach, a mission called π-MOVE (π for piezo) will verify piezo motors on the developed platform. These piezo motors are representative for components of complex systems, as this motor concept is considered to be key technology for future segmented mirror telescope missions. In the mission design process for this platform, strong emphasis is put on the robustness of the design, low complexity and realizability within the institute’s environment. The advantages through access to both university and industry resources will be taken. The feasibility of professional technology verification is highly dependent on the test plans, which are developed in cooperation with the experienced industrial partners.

Experimental Study on Fundamental Phenomena of Boiling by Using Heat Transfer Surface With Well-Defined Cavities Created by MEMS: The Effect of Spacing Between Cavities

2006 ◽  
Author(s):  
Takato Sato ◽  
Yasuo Koizumi ◽  
Hiroyasu Ohtake
Keyword(s):  
Heat Transfer ◽  
Nucleate Boiling ◽  
Micro Electro Mechanical System ◽  
Heat Transfer Surface ◽  
Cylindrical Shape ◽  
Main Role ◽  
Nucleate Boiling Heat Transfer ◽  
Mems Technology ◽  
Strong Convection ◽  
Artificial Cavity

Pool nucleate boiling heat transfer experiments were performed for water by using the well-controlled and -defined heat transfer surfaces. Artificial cavity(ies) was (were) created on the mirror-finished silicon plate of 0.525 mm thickness by utilizing the Micro-Electro Mechanical System (MEMS) technology. Each cavity had cylindrical shape. The diameter and the depth of the cavity were 10μm and 40μm, respectively. Experiments were performed in a range of a heat flux ∼6.0 × 104 W/m2 for distilled water. When the cavity interval was close, the horizontal and declining coalescence of bubble on the cavities were dominant. This vigorous bubble coalescence created strong convection. The heat carried by this convection took a main part in the heat transfer when cavities were close. As the cavity interval became wide, the horizontal and declining coalescence did not take place anymore. The coalescence was limited only to the vertical lift or no coalescence. In this situation, bubbles grew large on the cavities and absorbed latent heat sufficiently. Bubbles themselves took the main role of carrying heat away from the heat transfer surface when cavities were further apart.

Preheat Limits in Practical Combustor Design: Experiments and Simulations

2018 ◽  
Author(s):  
Aleksandr Fridlyand ◽  
Brian Sutherland ◽  
Paul Glanville
Keyword(s):  
Natural Gas ◽  
A Priori ◽  
Effective Means ◽  
External Source ◽  
Chemical Kinetic ◽  
Residual Energy ◽  
Spontaneous Ignition ◽  
Autoignition Temperature ◽  
Air Stream ◽  
Experimental Apparatus

Autoignition in commercial and residential gas appliances is typically a phenomenon to be avoided. The autoignition temperature for a particular fuel, defined as the minimum temperature at which spontaneous ignition will occur without an external source of energy, is often used to characterize this phenomenon. In the design of combustion systems, it is used to demarcate conditions where autoignition may occur. In an emerging class of residential and commercial heating, cooling, and power generation appliances, preheating air and fuel can provide an effective means of boosting the overall energy efficiency by recuperating residual energy in the exhaust and reinvesting it back into the thermodynamic process. In such applications, the design question to answer is: How much can the air and fuel be preheated without autoignition? The autoignition temperature, often determined experimentally and can vary as much as 100°C for methane, may not be the most useful metric in this context. This work describes the results of a recent experimental investigation into the preheat limits for autoignition of air and natural gas with the aim of recuperating as much heat as possible in a heat pump. The experimental apparatus consisted of an air-fuel mixer supplying preheated mixture to a radiant burner. The air was first heated in excess of 750°C, cool natural gas was injected into and mixed with the hot-air stream, and all while avoiding autoignition. The current capability to predict autoignition in such applications a priori was also assessed using available chemical kinetic models and numerical simulations.

scholarly journals Fabrication and Characteristic of a Double Piezoelectric Layer Acceleration Sensor Based on Li-Doped ZnO Thin Film

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 331 ◽  
Author(s):  
Chunpeng Ai ◽  
Xiaofeng Zhao ◽  
Sen Li ◽  
Yi Li ◽  
Yinnan Bai ◽  
...  
Keyword(s):  
Thin Film ◽  
Resonance Frequency ◽  
Piezoelectric Layer ◽  
Rf Magnetron Sputtering ◽  
Micro Electro Mechanical System ◽  
Test Results ◽  
Acceleration Sensor ◽  
Piezoelectric Layers ◽  
Mems Technology ◽  
Doped Zno

In this paper, a double piezoelectric layer acceleration sensor based on Li-doped ZnO (LZO) thin film is presented. It is constituted by Pt/LZO/Pt/LZO/Pt/Ti functional layers and a Si cantilever beam with a proof mass. The LZO thin films were prepared by radio frequency (RF) magnetron sputtering. The composition, chemical structure, surface morphology, and thickness of the LZO thin film were analyzed. In order to study the effect of double piezoelectric layers on the sensitivity of the acceleration sensor, we designed two structural models (single and double piezoelectric layers) and fabricated them by using micro-electro-mechanical system (MEMS) technology. The test results show that the resonance frequency of the acceleration sensor was 1363 Hz. The sensitivity of the double piezoelectric layer was 33.1 mV/g, which is higher than the 26.1 mV/g of single piezoelectric layer sensitivity, both at a resonance frequency of 1363 Hz.

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