Large Stroke Vertical PZT Microactuator With High-Speed Rotational Scanning

Single-pixel imaging technology is an attractive technology considering the increasing demand of imagers that can operate in wavelengths where traditional cameras have limited efficiency. Meanwhile, the miniaturization of imaging systems is also desired to build affordable and portable devices for field applications. Therefore, single-pixel imaging systems based on microelectromechanical systems (MEMS) is an effective solution to develop truly miniaturized imagers, owing to their ability to integrate multiple functionalities within a small device. MEMS-based single-pixel imaging systems have mainly been explored in two research directions, namely the encoding-based approach and the scanning-based approach. The scanning method utilizes a variety of MEMS scanners to scan the target scenery and has potential applications in the biological imaging field. The encoding-based system typically employs MEMS modulators and a single-pixel detector to encode the light intensities of the scenery, and the images are constructed by harvesting the power of computational technology. This has the capability to capture non-visible images and 3D images. Thus, this review discusses the two approaches in detail, and their applications are also reviewed to evaluate the efficiency and advantages in various fields.

Section: Electrothermal Actuationmentioning

confidence: 99%

Section: Electrothermal Actuationmentioning

confidence: 99%

Single-Pixel MEMS Imaging Systems

Zhou

Lim

2020

“…Taking advantage of the superior dynamic range of axial axis with dual-axis confocal architecture, researchers can also achieve vertical cross-sectional deep imaging (XZ-plane, like B-mode in US imaging) in scattering tissue in addition to the traditional horizontal cross-sectional imaging (or so-called en-face imaging) [ 77 , 78 , 79 , 80 , 81 , 82 ]. Instead of using traditional electrostatic or electro-thermal actuation mechanism [ 83 ], to meet the unmet needs in 3D imaging endomicroscope, a multi-fold based thin-film PZT based MEMS 3D scanner [ 84 , 85 , 86 ], show in Figure 12 , has been developed for piston-mode ( z -axis, axial focusing) movement with inner fast scanning ( z -axis), corresponding to the vertical cross-sectional ZX-plane. The MEMS chip is about 3 mm by 3 mm in footprint, which is sufficient for integration into the DAC endomicroscopic imaging instrument with OD 5.5 mm distal end.…”

Section: Confocal Endomicroscopementioning

confidence: 99%

New Endoscopic Imaging Technology Based on MEMS Sensors and Actuators

Qiu

Piyawattanamatha

2017

Self Cite

Over the last decade, optical fiber-based forms of microscopy and endoscopy have extended the realm of applicability for many imaging modalities. Optical fiber-based imaging modalities permit the use of remote illumination sources and enable flexible forms supporting the creation of portable and hand-held imaging instrumentations to interrogate within hollow tissue cavities. A common challenge in the development of such devices is the design and integration of miniaturized optical and mechanical components. Until recently, microelectromechanical systems (MEMS) sensors and actuators have been playing a key role in shaping the miniaturization of these components. This is due to the precision mechanics of MEMS, microfabrication techniques, and optical functionality enabling a wide variety of movable and tunable mirrors, lenses, filters, and other optical structures. Many promising results from MEMS based optical fiber endoscopy have demonstrated great potentials for clinical translation. In this article, reviews of MEMS sensors and actuators for various fiber-optical endoscopy such as fluorescence, optical coherence tomography, confocal, photo-acoustic, and two-photon imaging modalities will be discussed. This advanced MEMS based optical fiber endoscopy can provide cellular and molecular features with deep tissue penetration enabling guided resections and early cancer assessment to better treatment outcomes.

“…An example was reported in reference [46], where a thin-film piezoelectric microactuator comprised of PZT was implemented and purposed for obtaining both lateral and vertical cross-sectioning in endoscopic dual-axes confocal imaging. In the MEMS architecture employing an SOI process flow, a dog-bone shaped mirror is connected to a gimbal platform by beam flexures, and the gimbal base is supported by outer folded legs with embedded thin-film PZT.…”

Section: Piezoelectric Actuationmentioning

confidence: 99%

Progress of MEMS Scanning Micromirrors for Optical Bio-Imaging

Lin

Keeler

2015

Microelectromechanical systems (MEMS) have an unmatched ability to incorporate numerous functionalities into ultra-compact devices, and due to their versatility and miniaturization, MEMS have become an important cornerstone in biomedical and endoscopic imaging research. To incorporate MEMS into such applications, it is critical to understand underlying architectures involving choices in actuation mechanism, including the more common electrothermal, electrostatic, electromagnetic, and piezoelectric approaches, reviewed in this paper. Each has benefits and tradeoffs and is better suited for particular applications or imaging schemes due to achievable scan ranges, power requirements, speed, and size. Many of these characteristics are fabrication-process dependent, and this paper discusses various fabrication flows developed to integrate additional optical functionality beyond simple lateral scanning, enabling dynamic control of the focus or mirror surface. Out of this provided MEMS flexibility arises some challenges when obtaining high resolution images: due to scanning non-linearities, calibration of MEMS scanners may become critical, and inherent image artifacts or distortions during scanning can degrade image quality. Several reviewed methods and algorithms have been proposed to address these complications from MEMS scanning. Given their impact and promise, great effort and progress have been made toward integrating MEMS and biomedical imaging.