Algorithms for On-Line Monitoring of Micro Spheres in an Optical Tweezers-Based Assembly Cell

2007 ◽  
Vol 7 (4) ◽  
pp. 330-338 ◽  
Author(s):  
Tao Peng ◽  
Arvind Balijepalli ◽  
Satyandra K. Gupta ◽  
Tom LeBrun
Keyword(s):  
Optical Tweezers ◽  
Three Dimensional ◽  
Optical Section ◽  
Automated Assembly ◽  
Glass Microspheres ◽  
Assembly Cell ◽  
Computational Speed ◽  
On Line ◽  
Areas Of Interest ◽  
Speed And Accuracy

Optical tweezers have emerged as a powerful tool for micro- and nanomanipulation. Using optical tweezers to perform automated assembly requires on-line monitoring of components in the assembly workspace. This paper presents algorithms for estimating three-dimensional positions of microspheres in the assembly workspace. Algorithms presented in this paper use images obtained by optical section microscopy. The images are first segmented to locate areas of interest and then image gradient information from the areas of interest is used to locate the positions of individual micro spheres in the XY plane. Finally, signature curves are computed and utilized to obtain the Z locations of spheres. We have tested these algorithms with glass microspheres of two different sizes under different illumination conditions. Our experiments indicate that the algorithms described in this paper provide sufficient computational speed and accuracy to support the operation of optical tweezers.

Algorithms for On-Line Monitoring of Components in an Optical Tweezers-Based Assembly Cell

2006 ◽  
Author(s):  
Tao Peng ◽  
Arvind Balijepalli ◽  
Satyandra K. Gupta ◽  
Thomas W. LeBrun
Keyword(s):  
Optical Tweezers ◽  
Optical Section ◽  
Metallic Nanowires ◽  
Automated Assembly ◽  
3 Dimensional ◽  
Image Gradient ◽  
Assembly Cell ◽  
On Line ◽  
Assembly Operations ◽  
Areas Of Interest

Optical tweezers have emerged as a powerful tool for micro and nanomanipulation. Using optical tweezers to perform automated assembly requires on-line monitoring of components in the assembly workspace. This paper presents algorithms for estimating positions and orientations of microscale and nanoscale components in the 3-Dimensional assembly workspace. Algorithms presented in this paper use images obtained by optical section microscopy. The images are first segmented to locate areas of interest and then image gradient information from the areas of interest is used to generate probable locations and orientations of components in the XY-plane. Finally, signature curves are computed and utilized to obtain component locations and orientations in 3-D space. We have tested these algorithms with silica micro-spheres as well as metallic nanowires. We believe that the algorithms described in this paper will provide the foundation for realizing automated assembly operations in optical tweezers-based assembly cells.

Algorithms for Extraction of Nanowires Attributes From Optical Section Microscopy Images

2007 ◽  
Author(s):  
Tao Peng ◽  
Arvind Balijepalli ◽  
Satyandra K. Gupta ◽  
Thomas W. LeBrun
Keyword(s):  
Optical Tweezers ◽  
Building Blocks ◽  
Optical Section ◽  
Extraction Techniques ◽  
Automated Assembly ◽  
Assembly Cell ◽  
Cell Components ◽  
Gradient Based ◽  
Areas Of Interest ◽  
Microscopy Images

Optical tweezers have emerged as a unique tool for micro and nanomanipulation. In an optical tweezers-based assembly cell, components are usually suspended in a fluidic medium and undergo constant random Brownian motion. Automated assembly using optical tweezers requires online monitoring of components in the assembly workspace. Nanowires are very important building blocks for constructing nanoscale devices. This paper presents algorithms for estimating length, location, and orientation of nanowires in the workspace using images obtained by optical section microscopy. The images are first segmented to locate general areas of interest which are then analyzed to determine discrete nanowire parameters. We use image gradient based techniques as well as feature extraction techniques to identify parameters of nanowire image patterns. These parameters are then used to estimate length, location, and orientation of nanowires.

Simulation of Automated Robotic Assembly

1995 ◽  
Author(s):  
Alec R. Miller ◽  
Raymond J. Cipra
Keyword(s):  
Manufacturing System ◽  
Three Dimensional ◽  
Robotic Assembly ◽  
Automated Assembly ◽  
System A ◽  
Assembly Cell ◽  
Wide Range ◽  
Graphical Visualization ◽  
Manufacturing Software ◽  
Research And Education

Abstract This paper examines the development of a networked simulation system. The Automated Robotic Manipulation (ARM) simulator is a central part of the network. This simulation tool currently assists with research and education into automated assembly. Robots, fixtures, conveyors, and parts create an automated assembly cell which is used to test advanced manufacturing software. ARM animates models of these physical components and enhances them with additional forms of three-dimensional graphical visualization. The feasibility of automated assembly can rapidly be assessed from the visual content presented by the simulator. Input formats for ARM are flexible enough to support a wide range of assembly cells and activities. Files and network transmissions customize the simulator to a particular assembly cell and its activities. The emerging assembly data protocol promotes the development of a truly integrated manufacturing system. A graphical interface complete with multiple views assists assembly cell layout and activity review, and networked operations significantly expand its role to areas such as interactive robot control and assembly preview.

Algorithms for Extraction of Nanowire Lengths and Positions From Optical Section Microscopy Image Sequence

2009 ◽  
Vol 9 (4) ◽  
Author(s):  
Tao Peng ◽  
Arvind Balijepalli ◽  
Satyandra K. Gupta ◽  
Thomas W. LeBrun
Keyword(s):  
Image Processing ◽  
Optical Tweezers ◽  
Image Sequence ◽  
Optical Section ◽  
Image Frame ◽  
Image Processing Techniques ◽  
Microscopy Image ◽  
Processing Techniques ◽  
Areas Of Interest ◽  
Microscopy Images

This paper presents algorithms for estimating length, location, and orientation of nanowires in a fluidic workspace using images obtained by optical section microscopy. Images containing multiple nanowires are first segmented to locate general areas of interest, which are then analyzed to determine discrete nanowire parameters. We use a set of image processing techniques to extract features of nanowire image patterns, e.g., boundary of nanowire, linear edges, and the intensity profile of nanowire’s diffraction fringes. The parameters of the features are then used to estimate length, 3D position, and 3D orientation of nanowires. A scene representing the workspace is reconstructed using the estimated attributes of nanowires, and it is constantly updated upon the capture of every image frame. We believe that the work described in this paper will be useful for assembly of nanowires using optical tweezers.

scholarly journals Computer-aided microtomography with true 3-D display in electron microscopy.

1986 ◽  
Vol 34 (1) ◽  
pp. 57-60 ◽  
Author(s):  
A C Nelson
Keyword(s):  
Electron Microscopy ◽  
Three Dimensional ◽  
Image Data ◽  
Floppy Disk ◽  
Video Camera ◽  
Primary Data ◽  
Video Tape ◽  
Display Device ◽  
On Line ◽  
Areas Of Interest

A novel research system has been designed to permit three-dimensional (3-D) viewing of high resolution image data from transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The system consists of front-end primary data acquisition devices, such as TEM and SEM machines, which are equipped with computer-controlled specimen tilt stages. The output from these machines is in analogue form, where a video camera attached to the TEM provides the sequential analogue image output while the SEM direct video output is utilized. A 10 MHz digitizer transforms the video image to a digital array of 512 X 512 pixel units of 8 bits deep-stored in a frame buffer. Digital images from multiple projections are reconstructed into 3-D image boxes in a dedicated computer. Attached to the computer is a powerful true 3-D display device which has hardware for graphic manipulations including tilt and rotate on any axis and for probing the image with a 3-D cursor. Data editing and automatic contouring functions are used to enhance areas of interest, and specialized software is available for measurement of numbers, distances, areas, and volumes. With proper archiving of reconstructed image sequences, a dynamic 3-D presentation is possible. The microtomography system is highly versatile and can process image data on-line or from remote sites from which data records would typically be transported on computer tape, video tape, or floppy disk.

Design and calibration of an IVEM for general 3-dimensional imaging of non-diffracting materials

1992 ◽  
Vol 50 (2) ◽  
pp. 1040-1041
Author(s):  
Neil Rowlands ◽  
Jeff Price ◽  
Michael Kersker ◽  
Seichi Suzuki ◽  
Steve Young ◽  
...  
Keyword(s):  
3D Imaging ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
3 Dimensional ◽  
3D Microstructure ◽  
Image Translation ◽  
Digital Correlation ◽  
On Line ◽  
Mechanical Stage ◽  
Projection Angle

Three-dimensional (3D) microstructure visualization on the electron microscope requires that the sample be tilted to different positions to collect a series of projections. This tilting should be performed rapidly for on-line stereo viewing and precisely for off-line tomographic reconstruction. Usually a projection series is collected using mechanical stage tilt alone. The stereo pairs must be viewed off-line and the 60 to 120 tomographic projections must be aligned with fiduciary markers or digital correlation methods. The delay in viewing stereo pairs and the alignment problems in tomographic reconstruction could be eliminated or improved by tilting the beam if such tilt could be accomplished without image translation.A microscope capable of beam tilt with simultaneous image shift to eliminate tilt-induced translation has been investigated for 3D imaging of thick (1 μm) biologic specimens. By tilting the beam above and through the specimen and bringing it back below the specimen, a brightfield image with a projection angle corresponding to the beam tilt angle can be recorded (Fig. 1a).

scholarly journals Membrane fusion studied by colloidal probes

2021 ◽  
Vol 50 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Hannes Witt ◽  
Filip Savić ◽  
Sarah Verbeek ◽  
Jörn Dietz ◽  
Gesa Tarantola ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Optical Tweezers ◽  
Three Dimensional ◽  
Biological Processes ◽  
Supported Membranes ◽  
Supported Bilayers ◽  
Force Microscopy ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Colloidal Probes

AbstractMembrane-coated colloidal probes combine the benefits of solid-supported membranes with a more complex three-dimensional geometry. This combination makes them a powerful model system that enables the visualization of dynamic biological processes with high throughput and minimal reliance on fluorescent labels. Here, we want to review recent applications of colloidal probes for the study of membrane fusion. After discussing the advantages and disadvantages of some classical vesicle-based fusion assays, we introduce an assay using optical detection of fusion between membrane-coated glass microspheres in a quasi two-dimensional assembly. Then, we discuss free energy considerations of membrane fusion between supported bilayers, and show how colloidal probes can be combined with atomic force microscopy or optical tweezers to access the fusion process with even greater detail.

The Use of Eye Tracking to Discern the Threshold at Which Metopic Orbitofrontal Deformity Attracts Attention

2020 ◽  
Vol 57 (12) ◽  
pp. 1392-1401
Author(s):  
Mark P. Pressler ◽  
Emily L. Geisler ◽  
Rami R. Hallac ◽  
James R. Seaward ◽  
Alex A. Kane
Keyword(s):  
Surgical Treatment ◽  
Graduate Students ◽  
Eye Tracking ◽  
Dwell Time ◽  
Surgical Intervention ◽  
Three Dimensional ◽  
Average Dwell Time ◽  
Eye Tracker ◽  
Gaze Patterns ◽  
Areas Of Interest

Introduction and Objectives: Surgical treatment for trigonocephaly aims to eliminate a stigmatizing deformity, yet the severity that captures unwanted attention is unknown. Surgeons intervene at different points of severity, eliciting controversy. This study used eye tracking to investigate when deformity is perceived. Material and Methods: Three-dimensional photogrammetric images of a normal child and a child with trigonocephaly were mathematically deformed, in 10% increments, to create a spectrum of 11 images. These images were shown to participants using an eye tracker. Participants’ gaze patterns were analyzed, and participants were asked if each image looked “normal” or “abnormal.” Results: Sixty-six graduate students were recruited. Average dwell time toward pathologic areas of interest (AOIs) increased proportionally, from 0.77 ± 0.33 seconds at 0% deformity to 1.08 ± 0.75 seconds at 100% deformity ( P < .0001). A majority of participants did not agree an image looked “abnormal” until 90% deformity from any angle. Conclusion: Eye tracking can be used as a proxy for attention threshold toward orbitofrontal deformity. The amount of attention toward orbitofrontal AOIs increased proportionally with severity. Participants did not generally agree there was “abnormality” until deformity was severe. This study supports the assertion that surgical intervention may be best reserved for more severe deformity.

Analysing the Natural Resting Aspects of a Component for Automated Assembly

1995 ◽  
Vol 209 (2) ◽  
pp. 125-131 ◽  
Author(s):  
B K A Ngoi ◽  
L E N Lim ◽  
S S G Lee ◽  
S W Lye
Keyword(s):  
Cross Sections ◽  
Computer Aided Design ◽  
Energy Barrier ◽  
Three Dimensional ◽  
Rectangular Prism ◽  
Automatic Assembly ◽  
Automated Assembly ◽  
Barrier Method ◽  
Aided Design ◽  
Natural Resting Aspect

This paper proposes the construction of an energy envelope that can be used to advantage with the energy barrier method to analyse the natural resting aspect of engineering parts destined for automatic assembly. Unlike the energy barrier method, the energy envelope does not require any visualization of the projection of the energy barrier on the aspect of interest. The energy envelope is the three-dimensional topology of the changes in height of the centroid, as the part attempts changes of aspect. The paper describes how it may be computed in a CAD (computer aided design) solid modeller. The results of applying the energy envelope to prisms of square and cylindrical cross-sections are the same as those predicted by the energy barrier method. When extended to the analysis of a rectangular prism, the results were consistent with Boothroyd's dynamic solution and Boothroyd's experimental data. This conclusion is encouraging as there is no irrefutable evidence that the energy barrier method may be applied to the analysis of the rectangular prism.

scholarly journals Assembly of multicomponent structures from hundreds of micron-scale building blocks using optical tweezers

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jeffrey E. Melzer ◽  
Euan McLeod
Keyword(s):  
Optical Tweezers ◽  
Three Dimensional ◽  
Building Blocks ◽  
Optical Tweezer ◽  
Device Fabrication ◽  
Positional Accuracy ◽  
Component Structure ◽  
Material Development ◽  
Critical Process Parameters ◽  
Optical Positioning

AbstractThe fabrication of three-dimensional (3D) microscale structures is critical for many applications, including strong and lightweight material development, medical device fabrication, microrobotics, and photonic applications. While 3D microfabrication has seen progress over the past decades, complex multicomponent integration with small or hierarchical feature sizes is still a challenge. In this study, an optical positioning and linking (OPAL) platform based on optical tweezers is used to precisely fabricate 3D microstructures from two types of micron-scale building blocks linked by biochemical interactions. A computer-controlled interface with rapid on-the-fly automated recalibration routines maintains accuracy even after placing many building blocks. OPAL achieves a 60-nm positional accuracy by optimizing the molecular functionalization and laser power. A two-component structure consisting of 448 1-µm building blocks is assembled, representing the largest number of building blocks used to date in 3D optical tweezer microassembly. Although optical tweezers have previously been used for microfabrication, those results were generally restricted to single-material structures composed of a relatively small number of larger-sized building blocks, with little discussion of critical process parameters. It is anticipated that OPAL will enable the assembly, augmentation, and repair of microstructures composed of specialty micro/nanomaterial building blocks to be used in new photonic, microfluidic, and biomedical devices.

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