title: Femtosecond laser rapid fabrication of large-area rose-like micropatterns on freestanding flexible graphene films.
abstract: We developed a simple, scalable and high-throughput method for fabrication of large-area three-dimensional rose-like microflowers with controlled size, shape and density on graphene films by femtosecond laser micromachining. The novel biomimetic microflower that composed of numerous turnup graphene nanoflakes can be fabricated by only a single femtosecond laser pulse, which is efficient enough for large-area patterning. The graphene films were composed of layer-by-layer graphene nanosheets separated by nanogaps (~10-50 nm), and graphene monolayers with an interlayer spacing of ~0.37 nm constituted each of the graphene nanosheets. This unique hierarchical layering structure of graphene films provides great possibilities for generation of tensile stress during femtosecond laser ablation to roll up the nanoflakes, which contributes to the formation of microflowers. By a simple scanning technique, patterned surfaces with controllable densities of flower patterns were obtained, which can exhibit adhesive superhydrophobicity. More importantly, this technique enables fabrication of the large-area patterned surfaces at centimeter scales in a simple and efficient way. This study not only presents new insights of ultrafast laser processing of novel graphene-based materials but also shows great promise of designing new materials combined with ultrafast laser surface patterning for future applications in functional coatings, sensors, actuators and microfluidics.
authors.affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, PR China.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Shi
authors.affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, PR China.
authors.forename: Lan
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Cluster Science, Ministry of Education, School of Chemistry, Beijing Instituteof Technology, Beijing 100081, PR China.
authors.forename: Liangti
authors.initials: L
authors.lastname: Qu
authors.affiliation: Key Laboratory of Cluster Science, Ministry of Education, School of Chemistry, Beijing Instituteof Technology, Beijing 100081, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Ran
authors.affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, PR China.
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, PR China.
authors.forename: Tianbao
authors.initials: T
authors.lastname: Ma
authors.affiliation: Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0511, USA.
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Lu