声操控型微流控芯片的加工与测试技术

介绍了一种声操控型微流控芯片的加工方法与测试技术。首先,基于声操控型微流控芯片的工作原理和功能需求设计了硬质微流控芯片的基本结构,采用激光切割方法实现了聚甲基丙烯酸甲酯（polymethylmethacrylate,简称PMMA）材质开放边界微流道的加工,采用数控加工（computerized numerical control,简称CNC）精雕方法实现了封闭边界微流道的加工,通过光固化型（ultra violet,简称UV）胶实现了硬质微流道与基板的室温封接,利用表面改性技术与毛细作用实现了芯片的无泵进样;其次,研究了不同加工工艺、工艺参数对微流道形貌的影响;最后,依据声操控微颗粒需求,综合仿真分析、阻抗测试及多普勒激光测振,选定了声操控型微流控芯片的工作频率,实现了微纳物体运动控制。该微流控芯片具有成本低、加工效率高及易于调整微流道结构的优点,在微纳操控、微纳制造和生化检测方面拥有广阔的应用前景。     

A stereovision model applied in bio‐micromanipulation system based on stereo light microscope

A bio‐micromanipulation system is designed for manipulating micro‐objects with a length scale of tens or hundreds of microns based on stereo light microscope. The world coordinate reconstruction of points on the surface of micro‐objects is an important goal for the micromanipulation. Traditional pinhole camera model is applied widely in macrocomputer vision. However, this model will output bad data with remarkable error if it is directly used to reconstruct three‐dimensional world coordinates for stereo light microscope. Therefore, a novel and improved pinhole camera model applied in bio‐micromanipulation system is proposed in this article. The new model is composed of binocular‐pinhole model and error‐correction model. The binocular‐pinhole model is used to output the basic world coordinates. The error‐correction model is used to correct the errors from the basic world coordinates and outputs the final high‐precision world coordinates. The results show that the new model achieves a precision of 0.01 mm in the X direction, 0.01 mm in the Y direction, and 0.015 mm in the Z direction within a maximum reconstruction distance of 4.1 mm in the X direction, 2.9 mm in the Y direction, and 2.25 mm in the Z direction, and that traditional pinhole camera model achieves a lower and unsatisfactory precision of about 0.1 mm.     

光的自旋和轨道角动量

光具有由偏振性决定的自旋角动量(SAM)和由光场空间分布决定的轨道角动量(OAM)两种不同的物理性质。重点对光的自旋和轨道角动量在光束生成和变换性质、存在形式和描述方法、力学效应、空间相干性和时间相干性、角向多普勒频移效应及参量转换与量子纠缠等方面进行对比,探索它们的现象学差别,以期更好地理解光的本性,为该领域的研究提供启发和拓展思路。总结和分析了轨道角动量的最新研究成果,并展望了该领域的最新研究动态。     

扫描电子显微镜结合热电离质谱测定单微粒中铀同位素比值

单微粒铀同位素分析是核保障环境监测技术的重要手段。作为现阶段应用最可靠且广泛的微粒分析技术之一,裂变径迹-热电离质谱(FT-TIMS)技术需依赖反应堆辐照,分析步骤繁琐,效率较低。扫描电子显微镜结合热电离质谱(SEM-TIMS)在保持原有TIMS的高测量精密度的同时,由扫描电子显微镜结合X射线能量色散谱仪(SEM-EDX)完成含铀微粒的寻找和鉴别,由微操作系统进行微粒转移,缩短了分析流程,提高了分析效率。本文应用建立的SEM-TIMS分析方法对已知同位素组成的单分散铀氧化物标准微粒进行了测量,测量结果与其标称值一致。     

Zernike矩和最小二乘椭圆拟合的亚像素边缘提取

为了提高微操作系统的装配精度,提出了一种新型的亚像素边缘检测和中心定位算法。应用Canny算子提取了微零件在像素级的边缘。应用Zernike矩对微零件进行亚像素级的边缘定位。采用最小二乘椭圆拟合定位微零件的中心位置。实验结果表明,该算法能够实现更高的定位精度和消耗更少的时间。     

面向微操作的宏/微精密定位技术研究

宏/微精密定位技术是微操作机器人的关键技术之一.在分析微操作机器人对宏微结合的精密定位技术需求的基础上,介绍了微米级宏动定位系统以及纳米级微动定位技术的实现方法.最后总结了压电陶瓷驱动纳米定位技术中的机构、驱动、检测、控制等关键问题的研究现状,并对微定位技术发展趋势进行了展望.     

核移植中的卵母细胞自动拨动研究(英文)

通过拨动细胞实现遗传物质的移动,并在对卵母细胞的拨动机理进行深入分析的基础上,根据极体是否可见将卵母细胞的自动拨动过程分为翻动和转动两部分。进一步的,对翻动过程中的卵母细胞进行建模,并通过实验首次提出并实现了四种卵母细胞的自动拨动轨迹。随后,对影响卵母细胞翻动幅度的因素进行了研究,并通过实验证实翻动的幅度可以通过拨动微针的离焦高度进行控制。最后,绵羊的大批量核移植操作应用结果表明,使用设计的自动拨动轨迹的移动遗传物质的成功率可达95%以上。同时,拨动过程中极体出现的位置也和本文提出的翻动模型计算的结果一致,从而验证了本文工作的有效性。     

Integrating Optical Force Sensing with Visual Servoing for Microassembly

For microassembly tasks uncertainty exists at many levels. Single static sensing configurations are therefore unable to provide feedback with the necessary range and resolution for accomplishing many desired tasks. In this paper we present experimental results that investigate the integration of two disparate sensing modalities, force and vision, for sensor-based microassembly. By integrating these sensing modes, we are able to provide feedback in a task-oriented frame of reference over a broad range of motion with an extremely high precision. An optical microscope is used to provide visual feedback down to micron resolutions, while an optical beam deflection technique (based on a modified atomic force microscope) is used to provide nanonewton level force feedback or nanometric level position feedback. Visually servoed motion at speeds of up to 2 mm/s with a repeatability of 0.17 m are achieved with vision alone. The optical beam deflection sensor complements the visual feedback by providing positional feedback with a repeatability of a few nanometers. Based on the principles of optical beam deflection, this is equivalent to force measurements on the order of a nanonewton. The value of integrating these two disparate sensing modalities is demonstrated during controlled micropart impact experiments. These results demonstrate micropart approach velocities of 80 m/s with impact forces of 9 nN and final contact forces of 2 nN. Within our microassembly system this level of performance cannot be achieved using either sensing modality alone. This research will aid in the development of complex hybrid MEMS devices in two ways; by enabling the microassembly of more complex MEMS prototypes; and in the development of automatic assembly machines for assembling and packaging future MEMS devices that require increasingly complex assembly strategies.     

一种基于操纵杆控制微操作系统三维运动的方法

介绍了一种操作杆控制微操作系统的三维运动的新方法,其利用一种通用的操纵杆,基于windows环境下,通过对微操作系统的步进电机部分进行细分控制和操纵杆特性参数的设定,利用立体视觉成像系统,实现微操作系统的三维运动精密控制,操作台行程50mm,控制精度可达0.3μm.