Matching Items (6)
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- All Subjects: Additive Manufacturing
- Creators: Jin, Kailong
Description
With increasing advance complexity in the structure to be 3D printed, the use of post processing removal of support structures has become more complicated thing due to the need of newer tool case to remove supports in such scenarios. Attempts have been made to study, research and experiment the dissolvable and recyclable photo-initiated polymeric resin that can be used to build support structure. Vat photo-polymerization method of manufacturing was selected due to wide range of materials that can be selected and researched which can have the potential to be selected further for large scale manufacturing. Deep understanding of the recyclable polymer was done by performing chemical and mechanical property test. Varying light intensities are used to study the curing properties and respective dissolving properties. In this thesis document, recyclable and dissolvable polymeric resin have been selected to print the support structures which can be later dissolved and recycled.The resin was exposed to varying light projections using grayscales of 255, 200 and 150 showing different dissolving time of each structure. Dissolving time of the printed parts were studied by varying the surface to volume ratios of the part. Higher the surface to volume ratios of the printed part resulted in lower time it takes to dissolve the part in the dissolving solution. The mechanical strengths of the recycled part were found to be pretty solid as compared to the freshly prepared resin, good sign of using it for multiple times without degrading its strength. Cactus shaped model was printed using commercial red resin and supports with the recyclable solution to deeply understand the working and dissolving properties of recyclable resin. Without any external efforts, the supports were easily dissolved in the solution, leaving the cactus intact. Further work is carried on printing Meta shaped gyroid lattice structure in effort to lower the dissolving time of the supports while maintaining enough mechanical stress. Future efforts will be made to conduct the rheology test and further lower the dissolving time as much it can to be ready for the commercial large scale applications.
ContributorsNawab, Prem Kalpesh (Author) / Li, Xiangjia (Thesis advisor) / Zhuang, Houlong (Committee member) / Jin, Kailong (Committee member) / Arizona State University (Publisher)
Created2023
Description
Creating 3D objects out of high performance polymers, such as polyimides, is notoriously difficult since the highly stable polymer backbone limits processibility without extreme conditions. However, designing the polyimide precursor to crosslink upon photoirradiation enables the additive manufacturing of polyimides into complex, 3D objects. Crosslinking the photoactive polyimide precursor forms a solid 3D organogel, then subsequent thermal treatment removes the sacrificial scaffold and simultaneously imidizes the precursor into a 3D polyimide. The collaborative efforts of the Long and Williams group at Virginia Tech created three chemically distinct photoactive polyimide precursors to additively manufacture 3D polyimide objects for aerospace applications and to maintain the nuclear stockpile. The first chapter of this dissertation introduces fully aromatic polyimides and the additive manufacturing techniques used to print photoactive polyimide precursors. The second chapter reviews the common pore forming methods typically utilized to develop porous polyimides for low dielectric applications. The following chapters investigate the impact of the sacrificial scaffold on the thermo-oxidative aging behavior of the polyimide precursors after imidization, then focuses on lowering the imidization temperature of the polyimide precursor using base catalysis. These investigations lead to the creation of photoactive polysalts with polyethylene glycol (PEG) side chains to develop 3D, porous polyimides with tunable morphologies. Varying the molecular weight and concentration of the PEG side chains along the backbone tuned the pore size, and the photoactive nature of the polyimide precursor enabled 3D, porous polyimides printed using digital light processing.
ContributorsVandenbrande, Johanna (Author) / Long, Timothy E (Thesis advisor) / Williams, Christopher B (Committee member) / Jin, Kailong (Committee member) / Seo, Eileen (Committee member) / Arizona State University (Publisher)
Created2023
Description
Combining 3D bio-printing and drug delivery are promising techniques tofabricate scaffolds with well controlled and patient-specific structures for tissue
engineering. In this study, silk derivatives of bioink were developed consisting of
silk fibroin and gelatin then 3D printed into scaffolds. The scaffolds would be
evaluated for small molecule release, cell growth, degradation, and morphology.
Preparations and design of the scaffolds are major parts of engineering and tissue
engineering. Scaffolds are designed to mimic extracellular matrix by providing
structural support as well as promoting cell attachment and proliferation with
minimum inflammation while degrading at a controlled rate. Scaffolds offers new
potentials in medicine by aiding in the preparation of personalized and controlled
release therapeutic systems.
ContributorsNg, Johnny (Author) / Rege, Kaushal (Thesis advisor) / Holloway, Julianne (Committee member) / Jin, Kailong (Committee member) / Arizona State University (Publisher)
Created2022
Description
I worked with Professor Long and the Long research group in the Biodesign Institute to develop an ultra-violet assisted direct ink write 3D printer to 3D print poly(amic acid) pendant salts for their group. The project included a proof of concept small format 3D printer and then the development of the full scale printer. I wrote custom code to run the printer and create complex models as well as code to automatic dispense the viscous polymer we were using.
ContributorsLogsdon, Andrew (Author) / Long, Timothy (Thesis director) / Jin, Kailong (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2021-12
ContributorsLogsdon, Andrew (Author) / Long, Timothy (Thesis director) / Jin, Kailong (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2021-12
ContributorsLogsdon, Andrew (Author) / Long, Timothy (Thesis director) / Jin, Kailong (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2021-12