I would like to thank my previous supervisor, A/P Wong Chee How, for his guidance, support, and encouragement throughout four years of this research. He has been very patient with me, giving me guidance in my research work, and encouraging me whenever I felt lost. I would also like to thank my current supervisor, A/P Du Hejun, for supporting me during my thesis submission and all the related documental requirements for my graduation.I would also like to thank Dr. Tang Chao. His relentless support on research, theory, and technical issue, and his encouragement have given me the strength and determination to complete my research. Additionally, I like to thank the technical advisory committee members, A/P S. N.Piramanayagam and A/P Yeong Wai Yee, who have also given me many valuable comments. I also wish to thank our group members for their support, in particular to Dr. Gan Ming Xuan and Mr. Chua Kok Hong Gregory who have helped me in the fabrication of samples and given me valuable comments on my research.In addition, I would like to give thanks to Nanyang Technology University for awarding me the research scholarship so that I have the opportunity to pursue a Ph.D. degree in Singapore. I would like to thank all professors, staffs, and students in Singapore Centre for 3D Printing (SC3DP) for all the encouragement and support.As importantly, I would like to thank my family and friends, both in Singapore and Vietnam.