FABRICATION AND CHARACTERIZATION OF NICKEL MICRO-TUBES THROUGH ELECTROFORMING: DEPOSITION OPTIMIZATION USING EVOLUTIONARY ALGORITHMS

Abstract

The realization of micro/nano level features in a controlled fashion has always been a challenging task. In this work, a robust micro-electroforming set-up is designed and developed with the most amenable technique to fabricate thin-walled metallic micro-tubes employing the bottom-up approach. Theoretical modeling to predict the concentration profile with pulse time variation per cycle and simulation to realize the uniform current density distribution between electrodes has been performed. Herein, retrofitting of table-top drilling set-up is proposed to perform pulse electrodeposition. Afterward, a series of experiments based on the concept of design of experiments (DOE) is conducted to understand the behavior of the process by varying the input parameters viz., duty cycle, time of deposition, etc. The fabricated micro-tubes have also been tested for their structural and mechanical characterization with the help of FESEM, EDAX, XRD, hardness testing, and surface roughness measurements. Moreover, an attempt has been made to model and optimize this micro fabrication process. The formulation of a multi-objective function and optimization utilizing two evolutionary algorithms, i.e., genetic algorithms (GA) and particle swarm optimization (PSO) were accomplished. Experiment with optimized parameters has been performed and the percentage error for output variables compared. Particle swarm optimization method has been found to have a slight edge over genetic algorithm in terms of optimization.