Dissertation/Thesis Abstract

Design and development of the roller imprinting process
by Vijayaraghavan, Athulan, Ph.D., University of California, Berkeley, 2009, 219; 3369206
Abstract (Summary)

This thesis discusses the design and development of the roller imprinting process. Roller imprinting is a mechanical deformation process to create microscale features in planar workpieces. Imprints are created by rolling a cylindrical imprint roll with raised features on its surface over a fixed workpiece. A procedural modeling methodology is presented for designing imprint rolls, the process tooling used in roller imprinting. The procedural methodology is developed with the goal of achieving high precision features at the microscale and uses iterative computational analysis of the imprinting process. A tiling mechanism is used to reduce the complexity of the computational analysis. The imprint roll is represented as a sum of repeating entities, or tiles; individual tiles are independently designed, and are then arrayed to generate the full set of roll features.

The procedural methodology uses subdivision surfaces as a design representation for the imprint rolls. Subdivision surfaces allow for rule-based arbitrary feature refinement and modification, while preserving geometric and analytic surface properties. The imprint rolls are represented as Catmull-Clark subdivision surfaces, and finite element analysis (FEA) of the imprinting process is applied in iteratively designing the rolls. Roll features are manipulated locally using the control point space, based on the local mismatch between the imprinted features and the required features. Regions of the roll can be selectively targeted for modification without affecting other features. Convergence criteria are developed based on the eigenvalues of the functions used in manipulating the features. The algorithm can be generalized for developing process tooling for other deformation processes, and offers a robust way for designing complex features. The thesis also discusses the design and fabrication of a simple roller imprinting device to create features in polymer substrates. The imprinter is fabricated by retrofitting a conventional three-axis machine tool.

The thesis concludes with recommendations for improving the procedural design methodology and with requirements for data structures that allow the development of integrated design and manufacturing tools. As the complexity and sophistication of products increase, these tools are essential in improving the efficiency and performance of manufacturing processes.

Indexing (document details)
Advisor: Dornfeld, David
Commitee: Sequin, Carlo, Zohdi, Tarek
School: University of California, Berkeley
Department: Mechanical Engineering
School Location: United States -- California
Source: DAI-B 70/08, Dissertation Abstracts International
Subjects: Mechanical engineering
Keywords: Manufacturing, Optimization, Roller imprinting, Subdivision surfaces
Publication Number: 3369206
ISBN: 9781109310627
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