光机二维扫描技术在激光共聚焦生物芯片扫描仪中的应用

介绍了应用于激光共聚焦生物芯片扫描仪中的光机二维扫描技术 ,即用振镜和f- θ扫描物镜构成其中一维的光扫描系统 ,用步进电机驱动扫描工作台移动构成另一维机械扫描系统 ,并在此基础上分析研究了光机二维扫描控制系统的设计。为快速、高精度激光共聚焦生物芯片扫描仪的研制作了新的有益尝试 ,并取得了初步的实验结果     

生物芯片及其荧光信号检测

系统介绍了生物芯片的概念和制造方法 ,重点讨论了生物芯片的荧光检测方法 ,并对不同的检测方法进行了对比和分析。总体来说 ,激光共聚焦芯片扫描仪的荧光检测灵敏度和扫描分辨力较高 ,而 CCD芯片扫描仪的荧光检测灵敏度和扫描分辨力较低 ,但 CCD芯片扫描仪的检测速度较快 ,成本也较低     

生物芯片及其荧光信号检测

系统介绍了生物芯片的概念和制造方法,重点讨论了生物芯片的荧光检测方法,并对不同的检测方法进行了对比和分析.总体来说,激光共聚焦芯片扫描仪的荧光检测灵敏度和扫描分辨力较高,而CCD芯片扫描仪的荧光检测灵敏度和扫描分辨力较低,但CCD芯片扫描仪的检测速度较快,成本也较低.     

生物芯片及其荧光信号检测

系统介绍了生物芯片的概念和制造方法,重点讨论了生物芯片的荧光检测方法,并对不同的检测方法进行了对比和分析.总体来说,激光共聚焦芯片扫描仪的荧光检测灵敏度和扫描分辨力较高,而CCD芯片扫描仪的荧光检测灵敏度和扫描分辨力较低,但CCD芯片扫描仪的检测速度较快,成本也较低.     

计算生物学研究所筹备会在上海召开

近日由中国科学院电工研究所和光电技术研究所共同承担的中科院知识创新工程重大项目“生物芯片仪器研制”通过专家验收。该项目是具有我国自主知识产权的生物芯片仪器，其中，激光共聚焦生物芯片扫描仪三种、生物芯片点样仪两种、CCD生物芯片检测仪六种。该项目的研究成果目前已实现了产品实用化。     

激光共聚焦生物芯片分析仪的二维扫描研究

本文阐述激光共聚焦生物芯片分析仪的组成及特点、CCD和PMT型分析仪的不同,评述了分析仪中的机械式X、Y扫描技术及其不足,着重介绍了光机二维扫描技术的特性、主要参数以及初步实验结果.     

双荧光标记生物芯片激光共聚焦检测系统

基于激光共聚焦检测原理,构建了针对荧光标记生物芯片的检测系统,对用Cy₃或Cy₅标记蛋白点样的玻片进行了扫描检测,并对采集的荧光数据信号进行了图像重建。针对实际荧光信号可能较微弱并存在较大动态范围的情况,采用形态学方法对图像进行滤波、增强处理,显著增强了图像质量。提出了标定系统信噪比和灵敏度的公式,并据此对检测实验结果进行了详细的分析计算,最终标定此激光共聚焦生物芯片检测系统的灵敏度约为0.1 fluo/μm²。     

线扫描准共焦荧光成像

为了克服目前生物芯片荧光检测方法中诸如系统结构复杂、检测速度慢、灵敏度低、成本高等缺点,提出了一种新型生物芯片荧光检测方法——线扫描准共焦荧光成像法,并搭建了初步原理性装置。用线扫描代替共聚焦中的点扫描,将二维扫描变为一维扫描,在保持高灵敏度的同时,增加了探测速度,简化了系统,降低了成本。为了验证方法的可行性,使用搭建的原理性装置对手工点样的低密度DNA生物芯片进行了荧光成像检测。实验结果显示,系统的空间分辨率18μm,在使用像素平均法降噪后,测量浓度为0.03μmol/l的探针溶液所得信噪比为5.5×102。这项技术综合了面成像检测方法的低成本、结构简单的优势和点共焦方法具有的高分辨率的优点,适合在实验室中对生物芯片进行检测研究。     

激光共聚焦扫描显微镜在微机电系统中的应用

在微机电系统中,三维微结构分析是对微加工工艺进行表征的一种重要手段。随着微机电系统研究的深入和产业化的需求,其微结构分析在微机电系统中的重要性日益凸现。激光共聚焦扫描显微镜因其高分辨率、非接触、数据结构分析快等优点,在微结构分析中得到了大量的应用。本文介绍激光共聚焦扫描显微镜的成像原理,重点介绍激光共聚焦显微镜在大角度测量和形貌分析中的应用。同时,与台阶仪、扫描电子显微镜和白光干涉仪相比较,指出激光共聚焦扫描显微镜在微结构分析中的优点和局限性。     

双激光共聚焦生物芯片荧光分析仪

由浙江大学和深圳益生堂生物企业有限公司承担的“双激光共聚焦生物芯片荧光分析仪”项目最近完成预期目标，并通过浙江省科技厅组织的鉴定。     

Bio-information scanning technology using an optical pick-up head

We have developed a low cost and a highly compact bio-chip detection technology by modifying a commercially available optical pick-up head for CD/DVD. The highly parallel and miniaturized hybridization assays are addressed by the fluorescence emitted by the DNA-chip using the optical pick-up head. The gap between the objective lens and the bio-chip is regulated by the focus servo during the detection of the fluorescence signal. High-resolution and high-speed scanning is effectively realized by this simple scanning system instead of utilizing high-precision mechanism. Regardless of achievement of effective detection mechanism, the technique of fluorescence detection can prove to be disadvantageous because of the low stability of the dyes with low S/N ratio and an expensive setup such as a PMT detector is always required for fluorescence detection. We propose, for the first time, a novel scanning scheme based on metal nanoparticles in combination with a bio-chip substrate having a phase change recording layer. We found that the phase change process is highly affected by the existence of the densely condensed metal nanoparticles on the phase change layer during the writing process of the pick-up head.     

动态聚焦激光振镜扫描系统的误差分析及图形校正算法

动态聚焦激光振镜扫描系统广泛应用于大幅面激光扫描领域,在实现振镜高速扫描的同时,必须要保证扫描图形的精度。本文从动态聚焦激光振镜扫描系统的原理入手,分析了动态聚焦激光振镜扫描系统图形误差产生的原因,并给出了扫描图形的误差校正模型和精确校正算法,并在华中科技大学快速成型中心的粉末烧结快速成型设备上进行了试验验证。     

Scanning properties of a resonant fiber-optic piezoelectric scanner

We develop a resonant fiber-optic scanner using four piezoelectric elements arranged as a square tube, which is efficient to manufacture and drive. Using coupled-field model based on finite element method, scanning properties of the scanner, including vibration mode, resonant frequency, and scanning range, are numerically studied. We also physically measure the effects of geometry sizes and drive signals on the scanning properties, thus providing a foundation for general purpose designs. A scanner adopted in a prototype of imaging system, with a diameter of ~2 mm and driven by a voltage of 10 V (peak to peak), demonstrates the scanning performance by obtaining an image of resolution target bars. The proposed fiber-optic scanner can be applied to micro-endoscopy that requires two-dimensional scanning of fibers.     

激光主动探测系统二维均匀扫描设计

二维扫描振镜是激光主动探测系统实现一定视场范围内扫描探测的重要部件.针对振镜非均匀扫描的缺陷,讨论了二维扫描振镜的工作原理,分析了扫描激光光斑全覆盖条件,推导了等间距扫描量与驱动信号之间的关系式,结合单片机控制电路,给出了均匀扫描的软件实现方法,并对实现均匀扫描的电路进行了时序分析.该方法过程简单,激光光斑的均匀采样易...     

An alternative flat scanner and micropositioning method for scanning probe microscope

An alternative flat scanner used for combining a scanning probe microscope with an inverted optical microscope is presented. The scanner has a novel structure basically consisting of eight identical piezoelectric tubes, metal flexure beams, and one sample mount. Because of the specially designed structure, the scanner is able to carry a sample of more than 120 g during imaging. By applying voltages of ±150 V, scanning range of more than 30 μm in three dimensions can be achieved. To improve the reliability of the stick-slip motion, a new method for sample micropositioning is proposed by applying a pulsed voltage to the piezotubes to produce a motion in the z-axis. Reliable translation of the sample has been thus accomplished with the step length from ～700 nm to 9 μm over a range of several millimeters. A homemade scanning probe microscope-inverted optical microscope system based on the scanner is described. Experimental results obtained with the system are shown.     

大口径精密光束扫描装置

高精度光束扫描、对准和跟踪是精密测控领域中的技术难点.基于棱镜偏摆角和光束偏离角存在百倍量级减速比的关系,提出采用级联正交偏摆双棱镜实现高精度光束扫描方案,并完成装置的研制,实现了大范围内精确控制光束偏转的要求.介绍装置的主要工作原理,给出设计指标和计算结果,接着介绍装置的机械结构、控制系统以及集成设计,分析前后棱镜变形和振动模态等问题,最后对装置进行试验标定.结果表明,扫描光束的俯仰角和方位角范围均达到1400 (rad,光束的扫描精度优于0.8 (rad,满足设计要求.装置的研制对于解决高精度的光学动静态跟瞄具有重要的工程意义.     

数字X线影像仪中激光扫描光学系统的设计

数字X线影像仪是计算机和激光技术快速发展的产物,而其中的激光扫描光学系统是其核心技术之一。针对数字X光影像仪的使用特点,对激光扫描系统中的Fθ镜头、光束扩展器、扫描器这几个关键部件进行了较详细的论述分析,提出并解决了其中一些关键问题,如光阑位置浮动对像质的影响、影响系统扫描光点大小的因素、扫描器的确定等。最后用ZEMAX光学设计软件对系统的光学性能进行了设计模拟,得到扫描光斑直径小于0.1mm、焦距和视场满足线性关系的设计结果。像质评价分析结果表明,所设计的镜头像质优良,轴上与轴外质量相当,像质达到衍射极限。     

Reconstruction of a scanned topographic image distorted by the creep effect of a Z scanner in atomic force microscopy

We analyzed the illusory slopes of scanned images caused by the creep of a Z scanner in an atomic force microscope (AFM) operated in constant-force mode. A method to reconstruct a real topographic image using two scanned images was also developed. In atomic force microscopy, scanned images are distorted by undesirable effects such as creep, hysteresis of the Z scanner, and sample tilt. In contrast to other undesirable effects, the illusory slope that appears in the slow scanning direction of an AFM scan is highly related to the creep effect of the Z scanner. In the controller for a Z scanner, a position-sensitive detector is utilized to maintain a user-defined set-point or force between a tip and a sample surface. This serves to eliminate undesirable effects. The position-sensitive detector that detects the deflection of the cantilever is used to precisely measure the topography of a sample. In the conventional constant-force mode of an atomic force microscope, the amplitude of a control signal is used to construct a scanned image. However, the control signal contains not only the topography data of the sample, but also undesirable effects. Consequently, the scanned image includes the illusory slope due to the creep effect of the Z scanner. In an automatic scanning process, which requires fast scanning and high repeatability, an atomic force microscope must scan the sample surface immediately after a fast approach operation has been completed. As such, the scanned image is badly distorted by a rapid change in the early stages of the creep effect. In this paper, a new method to obtain the tilt angle of a sample and the creep factor of the Z scanner using only two scanned images with no special tools is proposed. The two scanned images can be obtained by scanning the same area of a sample in two different slow scanning directions. We can then reconstruct a real topographic image based on the scanned image, in which both the creep effect of the Z scanner and the slope effect of the sample have been eliminated. The slope effect of the sample should be eliminated so as to avoid further distortion after removal of the creep effect. The creep effect can be removed from the scanned image using the proposed method, and a real topographic image can subsequently be efficiently reconstructed.     

A fast and versatile scan unit for scanning probe microscopy

In scanning probe microscopy (SPM), the image acquisition time is usually very long because of the limited speed with which the scanning device can trace the topography of the specimen under feed-back control. This limitation is often brought about by the natural frequency of the scanner in the direction perpendicular to the sample plane that confines the usable bandwidth of the feed-back loop. In this paper, we present a piezo-ceramic scanner that provides a large scan range and at the same time allows for adjustment of the probe-to-sample distance faster by about one order of a magnitude than a conventional setup. This is achieved through the combination of a large single tube scanner that provides a high-scan range and a small piezo element for swift motion in the direction perpendicular to the sample plane. The natural frequency in this direction lies at about 275 kHz. We outline the design considerations to avoid disturbing excitation of the scanner through the fast piezo element.