Development of Pulse Electroforming as a Fabrication Process for Functional Tubular Structures

Abstract

High-aspect ratio structures with micro/nano scale features are particularly essential newlineto act as interface components in the integration of microelectronics with the macrosystems. newlineHowever, in order to make such systems economically viable, parallel processbased newlinelow cost manufacturing techniques are desirable. Electroforming, as a fabrication newlinetechnique, presents itself as an alternate method. In this thesis attempts are made newlinefor the manufacturing of thin metallic tubular structures having thickness in microscale. newlineIt is further explored for the metallic substrate based growth and development of newlinesemiconductor metal oxide nanostructures. newlineIn order to ensure uniform wall thickness of the intended tubes, the design and newlinedevelopment of a rotating cathode electroforming equipment has been envisioned and newlinematerialized. The fabrication of nickel tubes has been realized through pulse newlineelectroforming by varying parameters such as duty cycle, time of deposition and newlinesurfactant (Sodium dodecyl sulfate) concentration. The tubes were characterized for newlinetheir hardness, surface roughness, crystallite size and compression strength. Further, newlineefforts are undertaken to optimize the electroforming process using evolutionary newlinetechniques such as Genetic algorithm and Particle swarm optimization for desired newlineoutput properties. A predictive model has also been developed utilizing Artificial newlineneural network for estimating accurately the hardness and surface roughness values of newlinethe tubes. newlineThe next part of the thesis deals with the growth of the semiconductor metal oxide newlinenanostructures on the fabricated nickel tubes to impart them with functionality. The newlinesemiconductor metal oxides are known for their photocatalytic behavior as well as newlineantibacterial activity. First, the feasibility of the growth on nickel tubular substrates newlinehas been explored through hydrothermal method.