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oe1(光电查) - 科学论文

11 条数据
?? 中文(中国)
  • PWM as a Low Cost Method for the Analog Control of MEMS Devices

    摘要: In this paper, we discuss the use of pulse width modulation (PWM) to control analog MEMS devices. We achieve a precise linear analog control of MEMS by applying PWM signal with a frequency well above the system’s mechanical natural frequency. We first demonstrate this using a parallel plate actuator and comb-drive, and then extend the technique to control a commercial deformable mirror. Such an approach allows the system designer to replace expensive drive electronics such as the high precision DACs and high voltage, linear amplifiers with a simple on-off switch. The advancements in the electronics industry tend to make precise timing cheaper and faster; our approach exploits these long-term trends to create low-cost control circuits. We also show how PWM control can linearize the positional response of the devices, where typically the position would depend quadratically on the applied analog voltage.

    关键词: linearize,pulse width modulation,Microelectromechanical systems,electrostatic actuator

    更新于2025-09-23 15:22:29

  • A Novel Transmitting Module Self-Monitoring Protection System Based On MEMS Sensors and Actuators

    摘要: Design, fabrication, and measurements of a novel transmitting module self-monitoring protection system are presented in this letter. Such a system is based on micro-electromechanical systems (MEMS) sensors and actuators for monitoring and protecting the microwave amplifier circuit. The transmitting module self-monitoring protection system consists of the RF MEMS switches, the directional coupler, and the MEMS power sensors. When the microwave amplifier circuit is at an abnormal state ("open," "short," or "overload"), the transmitting module self-monitoring protection system can isolate the microwave amplifier circuit out of order and reconfigure the transmitting module into impedance matching within 36 ms. When the microwave amplifier circuit is at the overload state, the error between the set switching power and the actual switching power is less than 9%. The measured results agree well with the theory.

    关键词: Microelectromechanical systems (MEMS) power sensor,microwave amplifier circuit,RF MEMS switch,self-monitoring protection

    更新于2025-09-23 15:22:29

  • [IEEE 2019 IEEE 2nd International Conference on Power and Energy Applications (ICPEA) - Singapore, Singapore (2019.4.27-2019.4.30)] 2019 IEEE 2nd International Conference on Power and Energy Applications (ICPEA) - Characteristics of Disturbance in Frequency 9 -150 kHz of Photovoltaic System under Fluctuated Solar Irradiance

    摘要: Gallium nitride (GaN) is a wide bandgap semiconductor material and is the most popular material after silicon in the semiconductor industry. The prime movers behind this trend are LEDs, microwave, and more recently, power electronics. New areas of research also include spintronics and nanoribbon transistors, which leverage some of the unique properties of GaN. GaN has electron mobility comparable with silicon, but with a bandgap that is three times larger, making it an excellent candidate for high-power applications and high-temperature operation. The ability to form thin-AlGaN/GaN heterostructures, which exhibit the 2-D electron gas phenomenon leads to high-electron mobility transistors, which exhibit high Johnson’s figure of merit. Another interesting direction for GaN research, which is largely unexplored, is GaN-based micromechanical devices or GaN microelectromechanical systems (MEMS). To fully unlock the potential of GaN and realize new advanced all-GaN integrated circuits, it is essential to cointegrate passive devices (such as resonators and filters), sensors (such as temperature and gas sensors), and other more than Moore functional devices with GaN active electronics. Therefore, there is a growing interest in the use of GaN as a mechanical material. This paper reviews the electromechanical, thermal, acoustic, and piezoelectric properties of GaN, and describes the working principle of some of the reported high-performance GaN-based microelectromechanical components. It also provides an outlook for possible research directions in GaN MEMS.

    关键词: HEMT,piezoelectric materials,micromachining,microelectromechanical systems,III-V,wide bandgap,resonators

    更新于2025-09-19 17:13:59

  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Investigating Industrial Metallization Solutions for Double-side Contact Passivated biPoly Solar Cells

    摘要: We present the design and fabrication of suspended optical waveguides on indium phosphide platform for use in an optical buffer device with MEMS actuation, in which the optical delay can be achieved by changing the spacing of the waveguides by electrostatic actuation. The optical and mechanical properties of the waveguides and pillar supports are modeled, and different MEMS actuation schemes are simulated. We also present fabrication and characterization results of the epitaxially grown sample structure and of the suspended waveguide device, exhibiting two parallel waveguides with submicron dimensions separated by a 400-nm air gap, and suspended at 40-μm intervals by S-shaped supports.

    关键词: microelectromechanical systems,indium phosphide,optical waveguides,III-V semiconductor materials,optical buffering

    更新于2025-09-19 17:13:59

  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Device model for intermediate band materials

    摘要: Gallium nitride (GaN) is a wide bandgap semiconductor material and is the most popular material after silicon in the semiconductor industry. The prime movers behind this trend are LEDs, microwave, and more recently, power electronics. New areas of research also include spintronics and nanoribbon transistors, which leverage some of the unique properties of GaN. GaN has electron mobility comparable with silicon, but with a bandgap that is three times larger, making it an excellent candidate for high-power applications and high-temperature operation. The ability to form thin-AlGaN/GaN heterostructures, which exhibit the 2-D electron gas phenomenon leads to high-electron mobility transistors, which exhibit high Johnson’s figure of merit. Another interesting direction for GaN research, which is largely unexplored, is GaN-based micromechanical devices or GaN microelectromechanical systems (MEMS). To fully unlock the potential of GaN and realize new advanced all-GaN integrated circuits, it is essential to cointegrate passive devices (such as resonators and filters), sensors (such as temperature and gas sensors), and other more than Moore functional devices with GaN active electronics. Therefore, there is a growing interest in the use of GaN as a mechanical material. This paper reviews the electromechanical, thermal, acoustic, and piezoelectric properties of GaN, and describes the working principle of some of the reported high-performance GaN-based microelectromechanical components. It also provides an outlook for possible research directions in GaN MEMS.

    关键词: wide bandgap,resonators,HEMT,micromachining,III-V,microelectromechanical systems,piezoelectric materials

    更新于2025-09-16 10:30:52

  • MEMS-enabled Silicon Photonic Integrated Devices and Circuits

    摘要: Photonic integrated circuits have seen a dramatic increase in complexity over the past decades. This development has been spurred by recent applications in datacenter communications and enabled by the availability of standardized mature technology platforms. Mechanical movement of wave-guiding structures at the micro- and nanoscale provides unique opportunities to further enhance functionality and to reduce power consumption in photonic integrated circuits. We here demonstrate integration of MEMS-enabled components in a simplified silicon photonics process based on IMEC’s Standard iSiPP50G Silicon Photonics Platform and a custom release process.

    关键词: Microelectromechanical Systems,Photonic Integrated Circuits,Nanophotonics,Integrated Optics,Silicon Photonics

    更新于2025-09-11 14:15:04

  • Large tunability of strain in WO3 single-crystal microresonators controlled by exposure to H2 gas

    摘要: Strain engineering is one of the most effective approaches to manipulate the physical state of materials, control their electronic properties, and enable crucial functionalities. Because of their rich phase diagrams arising from competing ground states, quantum materials are an ideal playground for on-demand material control, and can be used to develop emergent technologies, such as adaptive electronics or neuromorphic computing. It was recently suggested that complex oxides could bring unprecedented functionalities to the field of nanomechanics, but the possibility of precisely controlling the stress state of materials is so far lacking. Here we demonstrate the wide and reversible manipulation of the stress state of single-crystal WO3 by strain engineering controlled by catalytic hydrogenation. Progressive incorporation of hydrogen in freestanding ultra-thin structures determines large variations of their mechanical resonance frequencies and induces static deformation. Our results demonstrate hydrogen doping as a new paradigm to reversibly manipulate the mechanical properties of nanodevices based on materials control.

    关键词: Tungsten Trioxide,Hydrogen Doping,MicroElectroMechanical Systems,WO3,Transition Metal Oxides,Oxide MEMS,Strain Engineering,Chemical Strain

    更新于2025-09-11 14:15:04

  • Recent Progress on Photoacoustic Imaging Enhanced with Microelectromechanical Systems (MEMS) Technologies

    摘要: Photoacoustic imaging (PAI) is a new biomedical imaging technology currently in the spotlight providing a hybrid contrast mechanism and excellent spatial resolution in the biological tissues. It has been extensively studied for preclinical and clinical applications taking advantage of its ability to provide anatomical and functional information of live bodies noninvasively. Recently, microelectromechanical systems (MEMS) technologies, particularly actuators and sensors, have contributed to improving the PAI system performance, further expanding the research fields. This review introduces cutting-edge MEMS technologies for PAI and summarizes the recent advances of scanning mirrors and detectors in MEMS.

    关键词: acoustic delay line,MEMS scanning mirror,photoacoustic imaging,microring resonator,micromachined US transducer,microelectromechanical systems (MEMS)

    更新于2025-09-10 09:29:36

  • A MEMS Accelerometer Based on Wavelength Modulation Using an Integrated Blazed Grating

    摘要: This paper reports a MEMS optical fiber accelerometer with an integrated blazed grating as wavelength modulation component. The accelerometer includes a V-shape cantilever beam, a vertically symmetrical proof mass and an integrated blazed grating. The accelerometer prototype is fabricated with bulk micromachining processes and is tested. The bandwidth of the accelerometer is 200Hz. The optical sensitivity and nonlinearity of the measure range ±5.2g is 1.63nm/g @100Hz and 0.06% respectively. The x-axis and y-axis cross-axis sensitivities are 2% and 4.5% respectively. In the full temperature range of -20?C to 200 ?C, the temperature sensitivity is 2.8pm/ ?C. Thanks to the mentioned characteristics, the proposed MEMS accelerometer could have a wide range of applications, such as rail traffic and attitude heading sensing applications.

    关键词: blazed grating,microsensors,optical fiber sensors,micromachining,Accelerometers,Microelectromechanical systems

    更新于2025-09-10 09:29:36

  • Uncertainty Quantification of Microstructure—Governed Properties of Polysilicon MEMS

    摘要: In this paper, we investigate the stochastic effects of the microstructure of polysilicon films on the overall response of microelectromechanical systems (MEMS). A device for on-chip testing has been purposely designed so as to maximize, in compliance with the production process, its sensitivity to fluctuations of the microstructural properties; as a side effect, its sensitivity to geometrical imperfections linked to the etching process has also been enhanced. A reduced-order, coupled electromechanical model of the device is developed and an identification procedure, based on a genetic algorithm, is finally adopted to tune the parameters ruling microstructural and geometrical uncertainties. Besides an initial geometrical imperfection that can be considered specimen-dependent due to its scattering, the proposed procedure has allowed identifying an average value of the effective polysilicon Young’s modulus amounting to 140 GPa, and of the over-etch depth with respect to the target geometry layout amounting to O = ?0.09 μm. The procedure has been therefore shown to be able to assess how the studied stochastic effects are linked to the scattering of the measured input–output transfer function of the device under standard working conditions. With a continuous trend in miniaturization induced by the mass production of MEMS, this study can provide information on how to handle the foreseen growth of such scattering.

    关键词: microelectromechanical systems (MEMS),stochastic effects,parameter identification,coupled electromechanical analysis,polysilicon

    更新于2025-09-09 09:28:46