Fast wettability transition from hydrophilic to superhydrophobic laser-textured stainless steel surfaces under low-temperature annealing

Ngo, Chi-Vinh; Chun, Doo‐Man

doi:10.1016/j.apsusc.2017.03.038

Cited by 140 publications

(75 citation statements)

References 42 publications

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“…During the following days, Θ continuously increases, indicating a saturation-type behavior reaching values between 100 • and 140 • , in accordance with previous observations on several metals [29,34,35]. An explanation for this is given in [29] and [21]. A CO 2 decomposition reaction is triggered by the laser process and generates new non-polar carbon groups on the surface which have a hydrophobic character.…”

Section: Wetting Behaviorsupporting

confidence: 89%

“…The increased roughness, which is induced by laser treatment makes a Wenzel-like wetting more likely. This assumption is in accordance with other research groups [21,26,29]. In terms of the hydrophobic steady state after 12 days, which wetting state is present-the Wenzel, Cassie-Baxter, or Hybrid Cassie-Wenzel model-is still being debated [34].…”

Section: Structural Characterizationsupporting

confidence: 82%

“…In particular, the influence of LSFL on the wetting properties of surfaces can be applied in microfluidics [16] and to self-cleaning components [17]. Commonly, Ti/sapphire lasers [18][19][20] or nanosecond lasers [21][22][23][24] are used in scientific reports to modify the wetting behavior of surfaces; however, for industrial applications, it is desirable to use femtosecond lasers with a high repetition rate, enabling high throughput and process efficiency. There are fundamentally three different states of wetting behavior differentiated with respect to the contact angle, namely hydrophilic (Θ < 90 • ), hydrophobic (Θ > 90 • ), and super-hydrophobic (Θ > 150 • ).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Time Dependence of Wetting Behavior Upon Applying Hierarchic Nano-Micro Periodic Surface Structures on Brass Using Ultra Short Laser Pulses

et al. 2018

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We present a comprehensive experimental study on laser-induced hierarchic nano-micro periodic surface structures on brass that influences wetting behavior. Using ultra short laser pulses with a wavelength of 1030 nm, large scaled areas completely covered by laser-induced periodic surface structures (LIPSS) are generated with these areas being superimposed by ablation trenches and u-ripples. The influence of the incident laser fluence and pulse overlap on the apparent contact angle for coverage of the surface with distilled water with a surface tension of 74 mN/m are examined with its temporal evolution being observed over a period of two weeks. Our results show an initial drop in the apparent contact angle below the angle of an unstructured surface. Using atomic force microscopy, the roughness factor described by the Wenzel model is determined and compared to the roughness factor given by the apparent contact angle measurement. The ascertained difference in roughness cannot be entirely attributed to the topography of the laser-structured surface. We suggest that changes in the surface chemistry additionally alter the wetting behavior as confirmed by X-ray photoelectron spectroscopy (XPS) measurements. On a time scale of days after laser irradiation, the apparent contact angle increases into the hydrophobic range. Both the absolute apparent contact angle and this temporal change reveal a pronounced dependence on the applied laser fluence and pulse overlap. In particular, increasing both, the fluence and the pulse overlap leads to smaller apparent contact angles directly after the irradiation and to higher apparent contact angles after an observation period of two weeks.

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Section: Wetting Behaviorsupporting

confidence: 89%

Section: Structural Characterizationsupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Time Dependence of Wetting Behavior Upon Applying Hierarchic Nano-Micro Periodic Surface Structures on Brass Using Ultra Short Laser Pulses

et al. 2018

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“…Due to the hydrophobicity of the spin- coated graphene thin film, the PCR reagent has a large contact angle (CA) and height, as shown in Fig. These binary structures of the holearray patterns and the MLG sheets have demonstrated the wetting characteristics of the material surface, which can indicate that HA-RTC PCR device has wettability gradient surface Ngo and Chun, 2017). Fig.…”

Section: Resultsmentioning

confidence: 99%

Thermally stable and uniform DNA amplification with picosecond laser ablated graphene rapid thermal cycling device

Chen

Chang

et al. 2019

Biosensors and Bioelectronics

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Rapid thermal cycling (RTC) in an on-chip device can perform DNA amplification in vitro through precise thermal control at each step of the polymerase chain reaction (PCR). This study reports a straightforward fabrication technique for patterning an on-chip graphene-based device with hole arrays, in which the mechanism of surface structures can achieve stable and uniform thermal control for the amplification of DNA fragments. A thin-film based PCR device was fabricated using picosecond laser (PS-laser) ablation of the multilayer graphene (MLG). Under the optimal fluence of 4.72 J/cm 2 with a pulse overlap of 66%, the MLG can be patterned with arrays of 250 μm 2 hole surface structures. A 354-bp DNA fragment of VP1, an effective marker for diagnosing the BK virus, was amplified on an on-chip device in less than 60 min. A thin-film electrode with the aforementioned MLG as the heater was demonstrated to significantly enhance temperature stability for each stage of the thermal cycle. The temperature control of the heater was performed by means of a developed programmable PCR apparatus. Our results demonstrated that the proposed integration of a graphene-based device and a laser-pulse ablation process to form a thin-film PCR device has cost benefits in a small-volume reagent and holds great promise for practical medical use of DNA amplification.

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“…Recently, a solution combining nanosecond pulsed laser and heat treatment to prevent the usage of toxic chemicals and long fabrication time has been reported to form superhydrophobic copper [ 17 ], titanium [ 18 ], and aluminum grid-patterned surfaces [ 19 ]. However, research has focused mainly on the change in wetting behavior on only grid-patterned surfaces.…”

Section: Introductionmentioning

confidence: 99%

Controlling the Wetting Properties of Superhydrophobic Titanium Surface Fabricated by UV Nanosecond-Pulsed Laser and Heat Treatment

2018

Self Cite

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In this study, the effects of nanosecond-pulsed laser and pattern design were researched on the wettability of titanium material. Nanosecond-pulsed laser and heat treatment are used to fabricate superhydrophobic titanium surfaces. The effects of laser power (1–3 W) and step size (50–300 µm) on a microscale patterned titanium surface (line pattern and grid pattern) were investigated to explain the relation between microstructure and superhydrophobicity. The surface morphologies and wettability of the surfaces were analyzed by three-dimensional confocal microscopy and a contact angle meter. The results show that the laser power and pattern design affected the apparent contact angle (CA) and sliding angle (SA). The maximum step size, which could show superhydrophobicity with apparent CA > 150° and SA < 10°, was increased when the laser power increased from 1 to 3 W. Grid pattern showed isotropic wetting behavior, but line pattern showed both isotropic and anisotropic wetting behavior according to step size and laser power. Furthermore, when choosing the proper laser power and step size, the wetting properties of superhydrophobic surface such as lotus effect (apparent CA > 150° and SA < 10°) and petal effect (apparent CA > 150° and no SA) and isotropic/anisotropic behavior can be controlled for applications of water droplet control.

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Fast wettability transition from hydrophilic to superhydrophobic laser-textured stainless steel surfaces under low-temperature annealing

Cited by 140 publications

References 42 publications

Time Dependence of Wetting Behavior Upon Applying Hierarchic Nano-Micro Periodic Surface Structures on Brass Using Ultra Short Laser Pulses

Time Dependence of Wetting Behavior Upon Applying Hierarchic Nano-Micro Periodic Surface Structures on Brass Using Ultra Short Laser Pulses

Thermally stable and uniform DNA amplification with picosecond laser ablated graphene rapid thermal cycling device

Controlling the Wetting Properties of Superhydrophobic Titanium Surface Fabricated by UV Nanosecond-Pulsed Laser and Heat Treatment

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