Integrating CAD and Nano-Indentation for Complex Lithography

2012 ◽  
Author(s):  
Kangmin Xu ◽  
Seung-Cheol Yang ◽  
Xiaoping Qian
Keyword(s):  
Computer Aided Design ◽  
Geometric Features ◽  
Machining Parameters ◽  
Geometry Processing ◽  
B Splines ◽  
Nano Indentation ◽  
Atomic Force ◽  
Nanoscale Patterns ◽  
Aided Design ◽  
Straight Lines

We present an approach for producing complex nanoscale patterns by integrating computer-aided design (CAD) geometry processing with an atomic force microscope (AFM) based nanoindentation process. Surface modification is achieved by successive nano-indentation using a vibrating tip. By incorporating CAD geometry, this approach provides enhanced design and patterning capability for producing geometric features of both straight lines and freeform B-splines. This method automatically converts a pattern created in CAD software into a lithography plan for successive nanoindentation. For ensuring reliable lithography, key machining parameters including the interval of nanoindentation and the depth of nanogrooves have been investigated, and a proper procedure for determining the parameters has been provided. Finally, the automated nanolithography has been demonstrated on poly methylmethacrylate samples. It shows the robustness of the CAD integrated, AFM based nanoindentation approach in fabricating complex patterns.

Integrating Computer-Aided Design and Nano-Indentation for Complex Lithograph

2013 ◽  
Vol 1 (1) ◽  
Author(s):  
Kangmin Xu ◽  
Seung-Cheol Yang ◽  
Xiaoping Qian
Keyword(s):  
Computer Aided Design ◽  
Machining Parameters ◽  
Geometry Processing ◽  
B Splines ◽  
Nano Indentation ◽  
Atomic Force ◽  
Computer Aided ◽  
Nanoscale Patterns ◽  
Aided Design ◽  
Straight Lines

We present an approach for producing complex nanoscale patterns by integrating computer-aided design (CAD) geometry processing with an atomic force microscope (AFM) based nanoindentation process. Surface modification is achieved by successive nanoindentation using a vibrating tip. By incorporating CAD geometry, this approach provides enhanced design and patterning capability for producing geometric features of both straight lines and freeform B-splines. This method automatically converts a pattern created in CAD software into a lithography plan for successive nanoindentation. For ensuring reliable lithography, key machining parameters including the interval of nanoindentation and the depth of nanogrooves have been investigated, and a proper procedure for determining the parameters has been provided. Finally, the automated nanolithography has been demonstrated on poly methylmethacrylate (PMMA) samples. It shows the robustness of complex pattern fabrication via the CAD integrated, AFM based nanoindentation approach.

scholarly journals Generalized straight and curved beam theories with isogeometric analyis

2017 ◽  
Author(s):  
Ιωάννης Τσιπτσής
Keyword(s):  
Isogeometric Analysis ◽  
Computer Aided Design ◽  
State Of The Art ◽  
Curved Beam ◽  
Analog Equation Method ◽  
B Splines ◽  
Aided Design ◽  
Analog Equation ◽  
Beam Theories ◽  
Element Method

Στη διατριβή αυτή διερευνάται και επιλύεται σειρά προβλημάτων μέσω της ανάπτυξης εξελιγμένων προσομοιωμάτων ευθύγραμμης και καμπύλης δοκού. Πιο συγκεκριμένα, αντιμετωπίζονται τα προβλήματα ανομοιόμορφης στρέψης, γενικευμένης στρέβλωσης λόγω διάτμησης και στρέψης (μέσω των οποίων μελετάται το φαινόμενο της διατμητικής υστέρησης), διαστρέβλωσης (παραμόρφωση των διατομών της δοκού στο επίπεδό τους) καθώς και το πρόβλημα της δυναμικής ανάλυσης ευθύγραμμων και καμπύλων δοκών. Η αντιμετώπιση των προβλημάτων αυτών βασίζεται στη γενικευμένη διατύπωση καινοτόμων θεωριών δοκού (Generalized Beam Theories - GBT), με τις οποίες το πεδίο μετατοπίσεων και οι συνιστώσες των τανυστών παραμόρφωσης και τάσης διατυπώνονται ως γραμμικοί συνδυασμοί γινομένων μονοδιάστατων και διδιάστατων συναρτήσεων.Η αναλυτική λύση των μονοδιάστατων και διδιάστατων προβλημάτων συνοριακών και αρχικών-συνοριακών τιμών που μορφώνονται εν γένει δεν είναι εφικτή. Ως εκ τούτου, τα προβλήματα αυτά επιλύονται αριθμητικά εφαρμόζοντας τη Μέθοδο Συνοριακών Στοιχείων (Boundary Element Method - BEM), τη Μέθοδο Αναλογικής Εξίσωσης (Analog Equation Method - AEM), η οποία αποτελεί εξέλιξη της BEM, καθώς και τη Μέθοδο Πεπερασμένων Στοιχείων (Finite Element Method - FEM). Όσον αφορά στην επίλυση μονοδιάστατων προβλημάτων, οι αριθμητικές μέθοδοι που χρησιμοποιoύνται (AEM και FEM) συνδυάζονται με εργαλεία της Ισογεωμετρικής Ανάλυσης (Isogeometric Analysis - IGA) ώστε να επιτευχθεί μία προσέγγιση με χαμηλότερο υπολογιστικό κόστος καθώς και πιο διαδραστική μεταξύ ανάλυσης και γεωμετρίας που θα επιτυγχάνει πιο αξιόπιστα αποτελέσματα περιορίζοντας το σφάλμα που πηγάζει από την προσέγγιση της γεωμετρίας. Συγκεκριμένα, οι παραμετρικές καμπύλες B-splines και NURBS (Non-Uniform Rational B-Splines) που έχουν υιοθετήσει τα λογισμικά πακέτα μοντελοποίησης με υπολογιστή (Computer-Aided Design - CAD) εφαρμόζονται στην παρούσα διατριβή. Με βάση τις αναπτυχθείσες αναλυτικές και αριθμητικές διαδικασίες συντάσσονται καινοτόμα προγράμματα ηλεκτρονικού υπολογιστή για την ανάλυση τρισδιάστατων ευθύγραμμων και καμπυλόγραμμων ραβδωτών φορέων. Κάθε κύριο κεφάλαιο της διατριβής αποτελείται από την εισαγωγή, τη διατύπωση του προβλήματος, την αριθμητική επίλυση, αντιπροσωπευτικά αριθμητικά παραδείγματα και τα συμπεράσματα. Στην εισαγωγή κάθε κύριου κεφαλαίου περιέχεται η βιβλιογραφική επισκόπηση του ερευνητικού έργου (State of the Art) του αντίστοιχου εξεταζόμενου προβλήματος και παρουσιάζονται τα πρωτότυπα σχετικά στοιχεία της εργασίας. Τέλος, στο τελικό κεφάλαιο παρουσιάζονται τα συμπεράσματα και προτάσεις για μελλοντική έρευνα.

A Computer-Aided Design and Manufacturing Implementation of the Atomic Force Microscope Tip-Based Nanomachining Process for Two-Dimensional Patterning

2017 ◽  
Vol 5 (4) ◽  
Author(s):  
E. B. Brousseau ◽  
S. Thiery ◽  
B. Arnal ◽  
E. Nyiri ◽  
O. Gibaru ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Computer Aided Design ◽  
Two Dimensional ◽  
Atomic Force ◽  
Machining Errors ◽  
Computer Aided ◽  
Design And Manufacturing ◽  
Cad Cam ◽  
G Code ◽  
Aided Design

This paper reports a feasibility study that demonstrates the implementation of a computer-aided design and manufacturing (CAD/CAM) approach for producing two-dimensional (2D) patterns on the nanoscale using the atomic force microscope (AFM) tip-based nanomachining process. To achieve this, simple software tools and neutral file formats were used. A G-code postprocessor was also developed to ensure that the controller of the AFM equipment utilized could interpret the G-code representation of tip path trajectories generated using the computer-aided manufacturing (CAM) software. In addition, the error between a machined pattern and its theoretical geometry was also evaluated. The analyzed pattern covered an area of 20 μm × 20 μm. The average machined error in this case was estimated to be 66 nm. This value corresponds to 15% of the average width of machined grooves. Such machining errors are most likely due to the flexible nature of AFM probe cantilevers. Overall, it is anticipated that such a CAD/CAM approach could contribute to the development of a more flexible and portable solution for a range of tip-based nanofabrication tasks, which would not be restricted to particular customised software or AFM instruments. In the case of nanomachining operations, however, further work is required first to generate trajectories, which can compensate for the observed machining errors.

Curve and Surface Representation by Iterative B-Spline Fit to a Data Point Set

1987 ◽  
Vol 16 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Marilyn Lord
Keyword(s):  
Computer Aided Design ◽  
Control Point ◽  
The Body ◽  
B Spline ◽  
B Splines ◽  
Spline Surface ◽  
Data Points ◽  
Point Set ◽  
Support Surfaces ◽  
Aided Design

The method of B-splines provides a very powerful way of representing curves and curved surfaces. The definition is ideally suited to applications in Computer Aided Design (CAD) where the designer is required to remodel the surface by reference to interactive graphics. This particular facility can be advantageous in CAD of body support surfaces, such as design of sockets of limb prostheses, shoe insoles, and custom seating. The B-spline surface is defined by a polygon of control points which in general do not lie on the surface, but which form a convex hull enclosing the surface. Each control point can be adjusted to remodel the surface locally. The resultant curves are well behaved. However, in these biomedical applications the original surface prior to modification is usually defined by a limited set of point measurements from the body segment in question. Thus there is a need initially to define a B-spline surface which interpolates this set of data points. In this paper, a computer-iterative method of fitting a B-spline surface to a given set of data points is outlined, and the technique is demonstrated for a curve. Extension to a surface is conceptually straightforward.

Microstructure Feature Recognition for Materials Using Surfacelet-Based Methods for Computer-Aided Design-Material Integration

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Namin Jeong ◽  
David W. Rosen
Keyword(s):  
Computer Aided Design ◽  
Feature Recognition ◽  
Computational Method ◽  
Geometric Features ◽  
Material Microstructure ◽  
Control Material ◽  
Computer Aided ◽  
Aided Design ◽  
And Control ◽  
Material Information

With the material processing freedoms of additive manufacturing (AM), the ability to characterize and control material microstructures is essential if part designers are to properly design parts. To integrate material information into Computer-aided design (CAD) systems, geometric features of material microstructure must be recognized and represented, which is the focus of this paper. Linear microstructure features, such as fibers or grain boundaries, can be found computationally from microstructure images using surfacelet based methods, which include the Radon or Radon-like transform followed by a wavelet transform. By finding peaks in the transform results, linear features can be recognized and characterized by length, orientation, and position. The challenge is that often a feature will be imprecisely represented in the transformed parameter space. In this paper, we demonstrate surfacelet-based methods to recognize microstructure features in parts fabricated by AM. We will provide an explicit computational method to recognize and to quantify linear geometric features from an image.

Review on Non Uniform Rational B-Spline (NURBS): Concept and Optimization

2014 ◽  
Vol 903 ◽  
pp. 338-343
Author(s):  
Ali Munira ◽  
Nur Najmiyah Jaafar ◽  
Abdul Aziz Fazilah ◽  
Z. Nooraizedfiza
Keyword(s):  
Image Processing ◽  
Literature Review ◽  
Computer Aided Design ◽  
B Spline ◽  
B Splines ◽  
Curves And Surfaces ◽  
Geometry Design ◽  
Nurbs Curves ◽  
Computer Aided ◽  
Aided Design

This paper is to provide literature review of the Non Uniform Rational B-Splines (NURBS) formulation in the curve and surface constructions. NURBS curves and surfaces have a wide application in Computer Aided Geometry Design (CAGD), Computer Aided Design (CAD), image processing and etc. The formulation of NURBS showing that NURBS curves and surfaces requires three important parameters in controlling the curve and also modifying the shape of the curves and surfaces. Yet, curves and surfaces fitting are still the major problems in the geometrical modeling. With this, the researches that have been conducted in optimizing the parameters in order to construct the intended curves and surfaces are highlighted in this paper.

scholarly journals Approximation of Generalized Ovals and Lemniscates towards Geometric Modeling

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3325
Author(s):  
Valery Ochkov ◽  
Inna Vasileva ◽  
Ekaterina Borovinskaya ◽  
Wladimir Reschetilowski
Keyword(s):  
Computer Aided Design ◽  
Geometric Modeling ◽  
Three Dimensional ◽  
Numerical Data ◽  
Closed Curves ◽  
B Splines ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
High Smoothness ◽  
Aided Design

This paper considers an approach towards the building of new classes of symmetric closed curves with two or more focal points, which can be obtained by generalizing classical definitions of the ellipse, Cassini, and Cayley ovals. A universal numerical method for creating such curves in mathematical packages is introduced. Specific aspects of the provided numerical data in computer-aided design systems with B-splines for three-dimensional modeling are considered. The applicability of the method is demonstrated, as well as the possibility to provide high smoothness of the curvature profile at the specified accuracy of modeling.

Computer-Aided Design With Spatial Rational B-Spline Motions

1996 ◽  
Vol 118 (2) ◽  
pp. 193-201 ◽  
Author(s):  
B. Ju¨ttler ◽  
M. G. Wagner
Keyword(s):  
Computer Animation ◽  
Computer Aided Design ◽  
Control Structure ◽  
Basic Theory ◽  
Linear Control ◽  
Geometry Processing ◽  
B Spline ◽  
Computer Aided ◽  
Interpolation Techniques ◽  
Aided Design

Using rational motions it is possible to apply many fundamental B-spline techniques to the design of motions. The present paper summarizes the basic theory of rational motions and introduces a linear control structure for piecewise rational motions suitable for geometry processing. Moreover it provides algorithms for the calculation of the surface which is swept out by a moving polyhedron and examines interpolation techniques. The methods presented in this paper can be applied to various problems in computer animation as well as in robotics.

scholarly journals Robust approximation error estimates and multigrid solvers for isogeometric multi-patch discretizations

2018 ◽  
Vol 28 (10) ◽  
pp. 1899-1928 ◽  
Author(s):  
Stefan Takacs
Keyword(s):  
Error Estimates ◽  
Computer Aided Design ◽  
Convergence Rates ◽  
Approximation Error ◽  
Computational Domain ◽  
B Spline ◽  
B Splines ◽  
Multigrid Solvers ◽  
Aided Design ◽  
Real World Problems

In recent publications, the author and his coworkers have shown robust approximation error estimates for B-splines of maximum smoothness and have proposed multigrid methods based on them. These methods allow to solve the linear system arising from the discretization of a partial differential equation in Isogeometric Analysis in a single-patch setting with convergence rates that are provably robust both in the grid size and the spline degree. In real-world problems, the computational domain cannot be nicely represented by just one B-spline patch. In computer aided design, such domains are typically represented as a union of multiple patches. In this paper, we extend — for two-dimensional domains — the approximation error estimates and the multigrid solver to this multi-patch case.

Dynamic Modelling of Blades Based on a Novel Curved Thin Walled Beam Theory

2018 ◽  
Author(s):  
Juan C. Jauregui ◽  
Diego Cardenas ◽  
Hugo Elizalde ◽  
Oliver Probst
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Dynamic Modelling ◽  
Beam Theory ◽  
General Description ◽  
B Splines ◽  
Out Of Plane ◽  
Thin Walled ◽  
Aided Design

There are several Thin-Walled Beam models for straight beams, but few TWB models consider beams with arbitrary curvatures. Although, a curved beam can be modelled using finite elements, the number of degrees of freedom is too large and a nonlinear dynamic solution is very cumbersome, if not impossible. In this work, a general description of arbitrary three-dimensional curves, based on the Frenet-Serret field frame, is applied to determine the dynamic stresses in wing turbines blades. The dynamic model is developed using the Isogeometric Analysis (IGA) and the in plane and out-of-plane curvature’s gradients are found in an Euler-type formulation, allowing the treatment of cases with highly-curved geometry. An Isogeometrical (IGA) formulation relies on a linear combination of Non-Uniform Rational B-Splines (NURBS) to represent not just the model’s geometry, a standard practice in most Computer-Aided Design (CAD) platforms, but also the unknown solution field of each sought variable. For the unified model hitherto described, these variables are represented by a NURBS curve.

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