Closed-loop control of a 2-D mems micromirror with sidewall electrodes for a laser scanning microscope system

Chen, Hui; Chen, Albert; Sun, Wei; Sun, Zhendong; Yeow, John T. W.

doi:10.1080/15599612.2015.1095956

Cited by 9 publications

(2 citation statements)

References 25 publications

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“…In both experimental setups, the MAPM signals are verified by simultaneously measuring the 1D and 2D mirror motion on a PSD (On-Trak 2L10SP, Irvine, USA) as depicted in Figure 1. Using a PSD is a proven method for measuring MEMS mirror movement [15]. In addition to the PSD and the laser (JDS Uniphase HeNe Laser 1580P, Milpitas, USA), a beam splitter is used to minimize the distance between the mirror and the PSD to allow large scan angles.…”

Section: Mapm Design and Operationmentioning

confidence: 99%

Integrated Amplitude and Phase Monitor for Micro-Actuators

2022

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Micro-actuators driven on resonance maximize reach and speed; however, due to their sensitivity to environmental factors (e.g., temperature and air pressure), the amplitude and phase response must be monitored to achieve an accurate actuator position. We introduce an MEMS (microelectromechanical system) amplitude and phase monitor (MAPM) with a signal-to-noise ratio of 51 dB and 11.0 kHz bandwidth, capable of simultaneously driving and sensing the movement of 1D and 2D electrostatically driven micro-actuators without modifying the chip or its packaging. The operational principle is to electromechanically modulate the amplitude of a high-frequency signal with the changing capacitance of the micro-actuator. MAPM operation is characterized and verified by simultaneously measuring the amplitude and phase frequency response of commercial micromirrors. We demonstrate that the MAPM circuitry is insensitive to complex relationships between capacitance and position of the MEMS actuators, and it is capable of giving real-time read-out of the micromirror motion. Our measurements also reveal and quantify observations of phase drift and crosstalk in 2D resonant operation. Measurements of phase changes over time under normal operation also verify the need for phase monitoring. The open-loop, high-sensitivity position sensor enables detailed characterization of dynamic micro-actuator behavior, leading to new insights and new types of operation, including improved control of nonlinear motion.

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Section: Mapm Design and Operationmentioning

confidence: 99%

Integrated Amplitude and Phase Monitor for Micro-Actuators

2022

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“…2.0 mm). With the advent of microelectromechanical systems (MEMS) technology [21][22][23][24] , micromachined ultrasound transducers can be constructed with a smaller size. Therefore, such transducers can be promising as medical interventional imaging tools.…”

Section: Introductionmentioning

confidence: 99%

Capacitive micromachined ultrasound transducers for intravascular ultrasound imaging

et al. 2020

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Intravascular ultrasound (IVUS) is a burgeoning imaging technology that provides vital information for the diagnosis of coronary arterial diseases. A significant constituent that enables the IVUS system to attain high-resolution images is the ultrasound transducer, which acts as both a transmitter that sends acoustic waves and a detector that receives the returning signals. Being the most mature form of ultrasound transducer available in the market, piezoelectric transducers have dominated the field of biomedical imaging. However, there are some drawbacks associated with using the traditional piezoelectric ultrasound transducers such as difficulties in the fabrication of high-density arrays, which would aid in the acceleration of the imaging speed and alleviate motion artifact. The advent of microelectromechanical system (MEMS) technology has brought about the development of micromachined ultrasound transducers that would help to address this issue. Apart from the advantage of being able to be fabricated into arrays with lesser complications, the image quality of IVUS can be further enhanced with the easy integration of micromachined ultrasound transducers with complementary metal-oxide-semiconductor (CMOS). This would aid in the mitigation of parasitic capacitance, thereby improving the signal-to-noise. Currently, there are two commonly investigated micromachined ultrasound transducers, piezoelectric micromachined ultrasound transducers (PMUTs) and capacitive micromachined ultrasound transducers (CMUTs). Currently, PMUTs face a significant challenge where the fabricated PMUTs do not function as per their design. Thus, CMUTs with different array configurations have been developed for IVUS. In this paper, the different ultrasound transducers, including conventional-piezoelectric transducers, PMUTs and CMUTs, are reviewed, and a summary of the recent progress of CMUTs for IVUS is presented.

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