Additive manufacturing (AM), also known as three-dimensional (3D) printing, has received considerable interests in recent years. It enables fabrication of complex, customizable parts that would otherwise be too expensive or impossible for traditional manufacturing methods. 3D printing encompasses a wide variety of processes, including photopolymerization, material extrusion, selective laser sintering, directed energy deposition, and layer lamination. A major drawback for the mainstream 3D printing methods is their slow and successive nature of fabrication. 3D printing methods require the point-by-point addition of voxels to fabricate the designed structure. High-throughput processes, namely projection micro-stereolithography (PμSL) and micro-continuous liquid interface production (μCLIP), operate by curing one fabrication layer entirely with each exposure. μCLIP further improves the printing speed by making the fabrication fully continuous. These high-throughput processes, especially μCLIP, offer unprecedented flexibility in fabrication of customized prototypes.Unlike additive manufacturing, opto-mechanical devices like imaging systems have a much longer history ever since the first published use of telescope by Gallileo in 1610. However, modern imaging systems are suffering from obstacles such as slow and expensive fabrication procedure, difficulties in alignment, and restrictions on geometry of fabricated parts. Additive manufacturing has been reported to bring flexibility and miniaturization into optic realm but the solution to overcome the speed-accuracy trade-off in 3D printing has rarely been mentioned. Furthermore, the ability to fabricate key optical and optomechanical components and their cohesive assembly into a functional imaging system has yet to be shown. My research is focused on tackling the underlying speed-accuracy trade-off, in enabling scalable 3D printing of high-quality optical and opto-mechanical components towards integrated imaging devices and systems. I will first introduce the working principle of photopolymerization-based 3D printing technologies. In Chapter 2, I will present the method to overcome the speed-accuracy trade-off issue in 3D printing high-quality optical components using μCLIP process, resulting in the successful fabrication of an aspherical lens with 3.10 μm spatial resolution. This work brings a significant reduction in fabrication time for a millimeter-sized lens from hours to minutes and paves the way of introducing additive manufacturing towards the fabrication of functional imaging systems. Chapter 3 describes the effort in introducing additive manufacturing as a one-stop solution to fabricate customized imaging systems. Using a disposable miniature accommodating microscope as an example, Chapter 3 reports the method to unify the process for manufacturing its key optical and optomechanical components using a low-cost home-made μCLIP printer as a solution to create a fully customizable imaging platform. Chapter 4 describes the latest effort in creating a deadzone-free 3D printing system which enables the continuous printing without the use of oxygen permeable window, thereby eliminating the surface roughness induced by film-based oxygen permeable window and expand the printing area. Chapter 5 introduces my latest work on establishing multiphysics models to simulate the photopolymerization-based 3D printing process. The model I built successfully predicts the monomer conversion rate of photopolymerization process. Two representative 3D printing applications were discussed and simulated using the developed model. The models quantitatively describe the impact of printing parameters including layer thickness, image aberration and oxygen diffusion, etc. on the manufacturing accuracy and precision of 3D printing. Finally, Chapter 6 summarizes prospective future research directions for the work mentioned in Chapter 4 and 5.

Creator

• Hai, Rihan

DOI

• https://doi.org/10.21985/n2-xskj-w482

Subject

• Mechanical engineering

Language

• en

Alternate Identifier

• http://dissertations.umi.com/northwestern:16043
• etdadmin_upload_900931

Keyword

• Optical Imaging System
• Continuous Liquid Interface Production
• Additive Manufacturing

Date created

• 2022-01-01

Resource type

• Dissertation

Rights statement

• In Copyright