title: Additive and Photochemical Manufacturing of Copper.
abstract: In recent years, 3D printing technologies have been extensively developed, enabling rapid prototyping from a conceptual design to an actual product. However, additive manufacturing of metals in the existing technologies is still cost-intensive and time-consuming. Herein a novel platform for low-cost additive manufacturing is introduced by simultaneously combining the laser-induced forward transfer (LIFT) method with photochemical reaction. Using acrylonitrile butadiene styrene (ABS) polymer as the sacrificial layer, sufficient ejection momentum can be generated in the LIFT method. A low-cost continuous wave (CW) laser diode at 405 nm was utilized and proved to be able to transfer the photochemically synthesized copper onto the target substrate. The wavelength-dependent photochemical behaviour in the LIFT method was verified and characterized by both theoretical and experimental studies compared to 1064 nm fiber laser. The conductivity of the synthesized copper patterns could be enhanced using post electroless plating while retaining the designed pattern shapes. Prototypes of electronic circuits were accordingly built and demonstrated for powering up LEDs. Apart from pristine PDMS materials with low surface energies, the proposed method can simultaneously perform laser-induced forward transfer and photochemical synthesis of metals, starting from their metal oxide forms, onto various target substrates such as polyimide, glass and thermoplastics.
authors.affiliation: Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
authors.forename: Winco K C
authors.initials: WK
authors.lastname: Yung
authors.affiliation: Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.|School of Reliability and Systems Engineering, Beihang University, No. 37 Xueyuan RD. Haidian, Beijing 100191, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
authors.affiliation: Institute of Molecular Functional Materials and Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Hong Kong.
authors.forename: Zhengong
authors.initials: Z
authors.lastname: Meng
authors.affiliation: Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Huang
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Yingdi
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
authors.forename: Hang Shan
authors.initials: HS
authors.lastname: Choy
authors.affiliation: Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Cai
authors.affiliation: Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
authors.forename: Guijun
authors.initials: G
authors.lastname: Li
authors.affiliation: Institute of Molecular Functional Materials and Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Hong Kong.
authors.forename: Cheuk Lam
authors.initials: CL
authors.lastname: Ho
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Jinlong
authors.initials: J
authors.lastname: Yang
authors.affiliation: Institute of Molecular Functional Materials and Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Hong Kong.|Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
authors.forename: Wai Yeung
authors.initials: WY
authors.lastname: Wong