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Femtosecond laser rapid fabrication of large-area rose-like micropatterns on freestanding flexible graphene films.

Shi X, Li X, Jiang L, Qu L, Zhao Y, Ran P, Wang Q, Cao Q, Ma T, Lu Y - Sci Rep (2015)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, PR China.

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.

No MeSH data available.


Related in: MedlinePlus

(a–d) Fs laser large-area fabrication of graphene films with different densities of flower patterns. The inset image in (d) shows the water droplet on the patterned graphene film surface with a contact angle of ~150°. (e) Dependence of the contact angle and surface roughness on the density of the graphene microflowers, D, from 0 to 2.81.
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f5: (a–d) Fs laser large-area fabrication of graphene films with different densities of flower patterns. The inset image in (d) shows the water droplet on the patterned graphene film surface with a contact angle of ~150°. (e) Dependence of the contact angle and surface roughness on the density of the graphene microflowers, D, from 0 to 2.81.

Mentions: Large-area micropatterning of graphene films with controllable densities of flower patterns was realized by a simple scanning technique with coordinated adjustments of laser repetition rate, scanning speed (v), and scanning pitch. The details of the flower density (D) calculation, and the relation between scanning parameters and flower densities were described in Supplementary Table S1. Figure 5a–d show the SEM images of graphene films with different densities of flower patterns fabricated by fs laser direct writing at a fixed fluence of 1.1 J/cm2. It is shown that the graphene microflowers within the scanning area have almost the same geometrical feature, indicating the excellent repeatability. The density of graphene microflowers increases gradually from Fig. 5a–d, among which the surface with microflowers overlapped with each other in Fig. 5d shows the highest contact angle (CA) of ~150°. The static water contact angles of the micropatterned graphene films were measured to investigate the dependence of wettability on the density of flower patterns, as shown in Fig. 5e. The untreated graphene film exhibits hydrophilicity with CA of ~78°, while the CA of patterned surface increases dramatically to ~150°, reaching the superhydrophobic level. As the flower density can be tuned continuously, the contact angles between 78° and 150° can also be controlled.


Femtosecond laser rapid fabrication of large-area rose-like micropatterns on freestanding flexible graphene films.

Shi X, Li X, Jiang L, Qu L, Zhao Y, Ran P, Wang Q, Cao Q, Ma T, Lu Y - Sci Rep (2015)

(a–d) Fs laser large-area fabrication of graphene films with different densities of flower patterns. The inset image in (d) shows the water droplet on the patterned graphene film surface with a contact angle of ~150°. (e) Dependence of the contact angle and surface roughness on the density of the graphene microflowers, D, from 0 to 2.81.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663466&req=5

f5: (a–d) Fs laser large-area fabrication of graphene films with different densities of flower patterns. The inset image in (d) shows the water droplet on the patterned graphene film surface with a contact angle of ~150°. (e) Dependence of the contact angle and surface roughness on the density of the graphene microflowers, D, from 0 to 2.81.
Mentions: Large-area micropatterning of graphene films with controllable densities of flower patterns was realized by a simple scanning technique with coordinated adjustments of laser repetition rate, scanning speed (v), and scanning pitch. The details of the flower density (D) calculation, and the relation between scanning parameters and flower densities were described in Supplementary Table S1. Figure 5a–d show the SEM images of graphene films with different densities of flower patterns fabricated by fs laser direct writing at a fixed fluence of 1.1 J/cm2. It is shown that the graphene microflowers within the scanning area have almost the same geometrical feature, indicating the excellent repeatability. The density of graphene microflowers increases gradually from Fig. 5a–d, among which the surface with microflowers overlapped with each other in Fig. 5d shows the highest contact angle (CA) of ~150°. The static water contact angles of the micropatterned graphene films were measured to investigate the dependence of wettability on the density of flower patterns, as shown in Fig. 5e. The untreated graphene film exhibits hydrophilicity with CA of ~78°, while the CA of patterned surface increases dramatically to ~150°, reaching the superhydrophobic level. As the flower density can be tuned continuously, the contact angles between 78° and 150° can also be controlled.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, PR China.

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.

No MeSH data available.


Related in: MedlinePlus