Advanced techniques for chemical gradient, eutectic metal, and crystallized polymer film additive manufacturing

Electrohydrodynamic jet (E-jet);Chemical gradient;Eutectic metal;Polymer film;Crystallized polymer film;Slot die head;Microstructure slot die head

Kieffer, Spencer Joseph ; Alleyne ; Andrew G.

关键词: Electrohydrodynamic jet (E-jet);    Chemical gradient;    Eutectic metal;    Polymer film;    Crystallized polymer film;    Slot die head;    Microstructure slot die head;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/98175/KIEFFER-THESIS-2017.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This thesis outlines three advanced manufacturing techniques used to print materials and manufacture devices in novel ways. First, E-jet printing is used to manufacture chemical gradients in a hydrogel. A chemical gradient acts like a sort of chemically specific attractor that collects analyte in a specified regions. Although these devices have been made using a pipette before, E-jet manufactured devices were made smaller and with a ~10x improved analyte collection capacity. Furthermore, controlled patterning of these wells on a hydrogel surface was demonstrated, which could not be achieved before. Lastly, the technique was used to demonstrate a well’s capacity to collect organophosphates, toxic compounds found in pesticides and chemical weapons, which can be used to decrease the detection limit for these harmful chemicals. Secondly, attempts to print low melting point metal eutectics using an E-jet printer are described. Unsuccessful techniques are likewise described so that they may be avoided in the future. A system to print metal eutectics by E-jet is devised and outlined so that future researchers can expediate the process of printing metal eutectics. Thirdly, a slot die printing technique to manufacture crystallized polymer films is described. The slot die printing head is of a novel design, using microstructures etched into the head to induce specific flows that cause polymers to crystallize. Two systems are either built or adapted for this printing technique. The first is a batch process system. The system is used to iterate quickly through different processing parameters to find those that are most successful at inducing crystallization. Crossed Polarizing Optical Microscopy (CPOM) is used to demonstrate that the process does indeed induce polymer crystallization. The second system is a roll-to-roll system, adapted from an existing roll-to-roll platform, meant to make the process continuous and allow for film patterning. The ability to print in a variety of regimes in a continuous fashion is demonstrated, but some mechanical and control design must still be implemented to improve the webbing motion.