The Improvement of Performance through Minimizing Scallop Size in MEMS Based Micro Wind Turbine

In this paper we report on the improvement of performance by minimizing scallop size through deep reactive-ion etching (DRIE) of rotors in micro-wind turbines based on micro-electro-mechanical systems (MEMS) technology. The surface profile of an MEMS rotor can be controlled by modifying the scallop size of the DRIE surface through changing the process recipe. The fabrication of a planar disk-type MEMS rotor through the MEMS fabrication process was carried out, and for the comparison of the improvements in the performance of each rotor, RPM testing and open circuit output voltage experiments of stators and permanent magnets were performed. We found that the smooth etching profile with a minimized scallop size formed using DRIE results in improved rotation properties in MEMS-based wind turbine rotors.

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Microscopic TV Holography for Microsystems Metrology

Defence Science Journal ◽

10.14429/dsj.61.908 ◽

2011 ◽

Vol 61 (5) ◽

pp. 491 ◽

Cited By ~ 1

Author(s):

Upputuri Paul Kumar ◽

U. Somasundaram ◽

M. P. Kothiyal ◽

Nandigana Krishna Mohan

Keyword(s):

Quantitative Measurement ◽

Imaging System ◽

Surface Profile ◽

Font Size ◽

Micro Electro Mechanical Systems ◽

Microscopic Imaging ◽

Mode Of Operation ◽

Mems Technology ◽

Working Distance

The continuously advancing Micro-Electro-Mechanical Systems (MEMS) technology requires a robust non-contact quantitative measurement system for the characterization of their performance, reliability and integrity. A TV holographic system with long working distance microscope is developed for the static, dynamic and 3-D surface profile characterization of Microsystems. The system can be operated either in continuous or stroboscopic illumination mode of operation. In this paper we present the development of a microscopic imaging system and its applications for Microsystems Metrology.Defence Science Journal, 2011, 61(5), pp.491-498, DOI:http://dx.doi.org/10.14429/dsj.61.908

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Novel Wind Energy Harvesting Device for City Building Based on ZnO Films Array

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.645-646.1139 ◽

2015 ◽

Vol 645-646 ◽

pp. 1139-1144 ◽

Cited By ~ 2

Author(s):

Shao Hua Wu ◽

Li Dong Du ◽

Zhan Zhao ◽

De Yi Kong ◽

Zhen Fang

Keyword(s):

Energy Harvesting ◽

Wind Energy ◽

Maximum Output Power ◽

Micro Electro Mechanical System ◽

Open Circuit ◽

Zno Films ◽

Maximum Output ◽

The Novel ◽

Mems Technology ◽

Circuit Output

A kind of novel wind energy harvesting device with square ZnO piezoelectric thin films array structure has been investigated in the article. It is designed and fabricated for ambient wind energy on high buildings in city blocks particularly. Ordinary elements of wind energy harvesting are various windmills or turbines, they are usually expensive and noisy, and are not suitable to be used in the crowed city. The novel wind energy harvesting device is fabricated by Micro Electro Mechanical System (MEMS) technology in order to avoid the deficiencies mentioned above. The films array has a multilayer structure with five layers, and has a thickness of about 2.5μm. The maximum open circuit output voltage of the device reaches 2.81V, and its maximum output power density is 23.39nW/cm2.

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Lead-Free LiNbO3 Thick Film MEMS Kinetic Cantilever Beam Sensor/Energy Harvester

Sensors ◽

10.3390/s22020559 ◽

2022 ◽

Vol 22 (2) ◽

pp. 559

Author(s):

Gabriel Barrientos ◽

Giacomo Clementi ◽

Carlo Trigona ◽

Merieme Ouhabaz ◽

Ludovic Gauthier-Manuel ◽

...

Keyword(s):

Electrical Energy ◽

Open Circuit ◽

Fabrication Process ◽

Lead Free ◽

Electromechanical Transduction ◽

Mems Fabrication ◽

Circuit Output ◽

Theoretical Considerations ◽

Modelling Simulation

In this paper, we present integrated lead-free energy converters based on a suitable MEMS fabrication process with an embedded layer of LiNbO3. The fabrication technology has been developed to realize micromachined self-generating transducers to convert kinetic energy into electrical energy. The process proposed presents several interesting features with the possibility of realizing smaller scale devices, integrated systems, miniaturized mechanical and electromechanical sensors, and transducers with an active layer used as the main conversion element. When the system is fabricated in the typical cantilever configuration, it can produce a peak-to-peak open-circuit output voltage of 0.208 V, due to flexural deformation, and a power density of 1.9 nW·mm−3·g−2 at resonance, with values of acceleration and frequency of 2.4 g and 4096 Hz, respectively. The electromechanical transduction capability is exploited for sensing and power generation/energy harvesting applications. Theoretical considerations, simulations, numerical analyses, and experiments are presented to show the proposed LiNbO3-based MEMS fabrication process suitability. This paper presents substantial contributions to the state-of-the-art, proposing an integral solution regarding the design, modelling, simulation, realization, and characterization of a novel transducer.

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Dynamic Modeling and Anti-Disturbing Control of an Electromagnetic MEMS Torsional Micromirror Considering External Vibrations in Vehicular LiDAR

Micromachines ◽

10.3390/mi12010069 ◽

2021 ◽

Vol 12 (1) ◽

pp. 69

Author(s):

Yong Hua ◽

Shuangyuan Wang ◽

Bingchu Li ◽

Guozhen Bai ◽

Pengju Zhang

Keyword(s):

Dynamic Model ◽

Optical Switching ◽

Control Method ◽

Sliding Mode ◽

Algorithm Design ◽

Coupling Model ◽

Micro Electro Mechanical Systems ◽

Mems Technology ◽

Torsional Micromirror ◽

Dynamic Coupling Model

Micromirrors based on micro-electro-mechanical systems (MEMS) technology are widely employed in different areas, such as optical switching and medical scan imaging. As the key component of MEMS LiDAR, electromagnetic MEMS torsional micromirrors have the advantages of small size, a simple structure, and low energy consumption. However, MEMS micromirrors face severe disturbances due to vehicular vibrations in realistic use situations. The paper deals with the precise motion control of MEMS micromirrors, considering external vibration. A dynamic model of MEMS micromirrors, considering the coupling between vibration and torsion, is proposed. The coefficients in the dynamic model were identified using the experimental method. A feedforward sliding mode control method (FSMC) is proposed in this paper. By establishing the dynamic coupling model of electromagnetic MEMS torsional micromirrors, the proposed FSMC is evaluated considering external vibrations, and compared with conventional proportion-integral-derivative (PID) controls in terms of robustness and accuracy. The simulation experiment results indicate that the FSMC controller has certain advantages over a PID controller. This paper revealed the coupling dynamic of MEMS micromirrors, which could be used for a dynamic analysis and a control algorithm design for MEMS micromirrors.

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A MEMS Fabrication Process with Thermal-Oxide Releasing Barriers and Polysilicon Sacrificial Layers for AlN Lamb-Wave Resonators to Achieve fs·Qm > 3.42 × 1012

Micromachines ◽

10.3390/mi12080892 ◽

2021 ◽

Vol 12 (8) ◽

pp. 892

Author(s):

Jicong Zhao ◽

Zheng Zhu ◽

Haiyan Sun ◽

Shitao Lv ◽

Xingyu Wang ◽

...

Keyword(s):

Resonant Frequency ◽

Lamb Wave ◽

Piezoelectric Layer ◽

Sacrificial Layer ◽

High Quality ◽

Micro Electro Mechanical Systems ◽

Mems Fabrication ◽

Thermal Oxide ◽

Series Resonant ◽

Releasing Process

This paper presents a micro-electro-mechanical systems (MEMS) processing technology for Aluminum Nitride (AlN) Lamb-wave resonators (LWRs). Two LWRs with different frequencies of 402.1 MHz and 2.097 GHz by varying the top interdigitated (IDT) periods were designed and fabricated. To avoid the shortcomings of the uncontrollable etching of inactive areas during the releasing process and to improve the fabrication yield, a thermal oxide layer was employed below the platted polysilicon sacrificial layer, which could define the miniaturized release cavities well. In addition, the bottom Mo electrode that was manufactured had a gentle inclination angle, which could contribute to the growth of the high-quality AlN piezoelectric layer above the Mo layer and effectively prevent the device from breaking. The measured results show that the IDT-floating resonators with 12 μm and 2 μm electrode periods exhibit a motional quality factor (Qm) as high as 4382 and 1633. The series resonant frequency (fs)·Qm values can reach as high as 1.76 × 1012 and 3.42 × 1012, respectively. Furthermore, Al is more suitable as the top IDT material of the AlN LWRs than Au, and can contribute to achieving an excellent electrical performances due to the smaller density, smaller thermo-elastic damping (TED), and larger acoustic impedance difference between Al and AlN.

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Vertical Axis Wind Turbine Performance Enhancement Via Utilizing the Repulsive Characteristics of Permanent Magnets

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1013/1/012026 ◽

2021 ◽

Vol 1013 ◽

pp. 012026

Author(s):

Sandesh Hegde ◽

C G Ramachandra

Keyword(s):

Wind Turbine ◽

Permanent Magnets ◽

Performance Enhancement ◽

Vertical Axis ◽

Vertical Axis Wind Turbine ◽

Turbine Performance

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Novel die-sinking micro-electro discharge machining process using microelectromechanical systems technology

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/09544062jmes323ft ◽

2006 ◽

Vol 220 (9) ◽

pp. 1481-1487 ◽

Cited By ~ 1

Author(s):

J-B Li ◽

K Jiang ◽

G J Davies

Keyword(s):

Microelectromechanical Systems ◽

Machining Process ◽

Metallic Surface ◽

Manufacturing Cost ◽

Sem Images ◽

Deep Reactive Ion Etching ◽

Electro Discharge Machining ◽

Mems Technology ◽

Fabrication Condition ◽

Edm Process

A novel die-sinking micro-electro discharge machining (EDM) process is presented for volume fabrication of metallic microcomponents. In the process, a high-precision silicon electrode is fabricated using deep reactive ion etching (DRIE) process of microelectromechanical systems (MEMS) technology and then coated with a thin layer of copper to increase the conductivity. The metalized Si electrode is used in the EDM process to manufacture metallic microcomponents by imprinting the electrode onto a flat metallic surface. The two main advantages of this process are that it enables the fabrication of metallic microdevices and reduces manufacturing cost and time. The development of the new EDM process is described. A silicon component was produced using the Surface Technology Systems plasma etcher and the DRIE process. Such components can be manufactured with a precision in nanometres. The minimum feature of the component is 50 μm. In the experiments, the Si component was coated with copper and then used as the electrode on an EDM machine of 1 μm resolution. In the manufacturing process, 130 V and 0.2 A currents were used for a period of 5 min. The SEM images of the resulting device show clear etched areas, and the electric discharge wave chart indicates a good fabrication condition. The experimental results have been analysed and the new micro-EDM process is found to be able to fabricate 25 μm features.

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Solvent-Based Polymer Swelling Characterization for the Development of the Nano/Micro-Particle Polymer Composite MEMS Corrosion Sensor

Volume 10: Micro- and Nano-Systems Engineering and Packaging ◽

10.1115/imece2014-40145 ◽

2014 ◽

Author(s):

Feng Pan ◽

Abdoul Kader Maiga ◽

Po-Hao Adam Huang

Keyword(s):

Reaction Products ◽

Material Transport ◽

Sensing Element ◽

Micro Electro Mechanical Systems ◽

Polymer Swelling ◽

Corrosion Sensor ◽

Mems Technology ◽

New Type ◽

Oxide Removal

The concept of using Micro-Electro-Mechanical Systems (MEMS) for in-situ corrosion sensing and for long-term applications has been proposed and is currently under development by our research lab. This is a new type of sensing using MEMS technology and, to the knowledge of our team, has not been explored previously. The MEMS corrosion sensor is based on the oxidation of metal nano/micro-particle embedded in elastomeric polymer to form a composite sensing element. The polymer controls the diffusion into and out of the sensor while the corrosion of the metal particles inhibits electrical conduction which is used as the detection signal. The work presented here is based on part of the methods developed for the removal of native and process-induced metal oxides. A major aspect is the study of the swelling dynamics of the polymer matrix (polydimethylsiloxane, PDMS) intended for enhancing material transport of etchants into and reaction products out of the composite during oxide removal. More specifically, the characterization of the swelling of copper particles-PDMS composite samples in liquid solvent baths is presented.

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A Miniature Optical Force Dual-Axis Accelerometer Based on Laser Diodes and Small Particles Cavities

Micromachines ◽

10.3390/mi12111375 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1375

Author(s):

Junji Pu ◽

Kai Zeng ◽

Yulie Wu ◽

Dingbang Xiao

Keyword(s):

Light Source ◽

Optical System ◽

High Sensitivity ◽

Measurement Range ◽

Optical Force ◽

Zero Bias ◽

Micro Electro Mechanical Systems ◽

Force Effect ◽

High Measurement ◽

Mems Technology

In recent years, the optical accelerometer based on the optical trapping force effect has gradually attracted the attention of researchers for its high sensitivity and high measurement accuracy. However, due to its large size and the complexity of optical path adjustment, the optical force accelerometers reported are only suitable for the laboratory environment up to now. In this paper, a miniature optical force dual-axis accelerometer based on the miniature optical system and a particles cavity which is prepared by Micro-Electro-Mechanical Systems (MEMS) technology is proposed. The overall system of the miniature optical levitation including the miniature optical system and MEMS particles cavity is a cylindrical structure with a diameter of about 10 mm and a height of 33 mm (Φ 10 mm × 33 mm). Moreover, the size of this accelerometer is 200 mm × 100 mm × 100 mm. Due to the selected light source being a laser diode light source with elliptical distribution, it is sensitive to the external acceleration in both the long axis and the short axis. This accelerometer achieves a measurement range of ±0.17 g–±0.26 g and measurement resolution of 0.49 mg and 1.88 mg. The result shows that the short-term zero-bias stability of the two orthogonal axes of the optical force accelerometer is 4.4 mg and 9.2 mg, respectively. The main conclusion that can be drawn is that this optical force accelerometer could provide an effective solution for measuring acceleration with an optical force effect for compact engineering devices.

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Design of Vertical Axis Wind Turbine Darrieus Type (H- Darrieus Rotor) of 0.20 KW from the Software Topsolid

Physical Science International Journal ◽

10.9734/psij/2020/v24i1130227 ◽

2020 ◽

pp. 52-70

Author(s):

Hagninou E. V. Donnou ◽

Drissa Boro ◽

Donald Abode ◽

Brunel Capo-Chichi ◽

Aristide B. Akpo

Keyword(s):

Wind Turbine ◽

Permanent Magnets ◽

Aerodynamic Force ◽

Low Cost ◽

Coastal Region ◽

Vertical Axis ◽

Digital Design ◽

Three Dimensions ◽

Geometrical Shape ◽

Vertical Axis Wind Turbine

The design of a vertical axis wind turbine (Darrieus type) adapted to the site of Cotonou in the coastal region of Benin was investigated. The statistical study of winds based on the Weibull distribution was carried out on hourly wind data measured at 10 m above the ground by the Agency for the Safety of Air Navigation in Africa and Madagascar (ASECNA) over the period from January 1981 to December 2014. The geometrical and functional parameters of the wind turbine were determined from different models and aerodynamic approaches. The digital design and assembly of the wind turbine components were carried out using the TOPSOLID software. The designed wind turbine has a power of 200W. It is equipped with a synchronous generator with permanent magnets and has three wooden blades with NACA 0015 profile. The optimal coefficient of lift and drag were estimated respectively at 0.7832 and 0.01578. The blades are characterized by an optimum angle of attack estimated at 6.25° with a maximum fineness of 49.63. Their length is 4 m and the maximum thickness is estimated at 0.03 m with a chord of 0.20 m. The volume and mass are respectively equal to 0.024 m3 and 36 kg. The aerodynamic stall occurs at an attack angle of 14.25°. The aerodynamic force exerted on these blades is estimated to be 240 N. The aerodynamic stresses exerted on the rotor are estimated at 15 864 504 Pa and the solidity at 0.27. The efficiency of the wind turbine is 0.323. From TOPSOLID, the geometrical shape of each component of the wind turbine is represented in three dimensions. The assembly allowed to visualizing the wind turbine after export via its graphical interface. The quantity of annual energy produced by the wind turbine was estimated at 0.85 MWh. This study is the first to be carried out in the study area and could reduce the technological dependence of vertical axis wind turbines and their import for low cost energy production.

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