Co-reporter:Jinglan Huo, Qing Yang, Feng Chen, Jiale Yong, Yao Fang, Jingzhou Zhang, Lin Liu, and Xun Hou
Langmuir April 18, 2017 Volume 33(Issue 15) pp:3659-3659
Publication Date(Web):March 19, 2017
DOI:10.1021/acs.langmuir.7b00393
Development of underwater superoleophobic surfaces has captured the imagination of researchers because of their applications; especially, oil manipulation based on such surfaces has attracted much attention. Here, we show a simple and effective way to fabricate an underwater transparent miniature “mechanical hand” based on controllable oil-adhesive patterned glass using a femtosecond laser. The underwater oil-adhesive force of the patterned glasses that compose the “mechanical hand” device can be controlled from ultralow to ultrahigh by adjusting the ratio of the untreated flat glass area to the laser-ablated rough area. These surfaces also showed favorable transparency in water. Various oils such as chloroform, hexadecane, n-dodecane, decane, liquid paraffin, and petroleum ether were tested, and their repellency against the as-prepared surfaces in water medium was confirmed. Moreover, the “mechanical hand” was used to implement oil transportation, fusion, and rapid capture, which can be applied in the construction of microfluidic devices, in situ detectors, and bioreactors.
Co-reporter:Jiale Yong;Qing Yang;Yao Fang;Jinglan Huo;Jingzhou Zhang;Xun Hou
Advanced Materials Interfaces 2017 Volume 4(Issue 20) pp:
Publication Date(Web):2017/10/01
DOI:10.1002/admi.201700552
AbstractIn this Communication, femtosecond laser is first used to successfully fabricate a slippery liquid infused porous surface (SLIPS). A kind of 3D porous network microstructure can be directly created on polyamide-6 (PA6) substrate by a one-step femtosecond laser direct writing method. The preparation process of SLIPS mainly includes three steps: femtosecond laser ablation, fluoroalkyl layer modification, and infusion of lubricating liquid. The porous layer and the substrate layer of this as-prepared SLIPS are inherent one material. Such SLIPS has many advantages over the most reported SLIPS fabricated based on “deposition/coating” methods whose porous layers are foreign materials against the substrates. A broad range of liquids including water, hexadecane, lake water, ink, glycerol, coffee, milk, egg white, and egg yolk can easily slide down the 10° tilted SLIPS, revealing that the resultant SLIPS has excellent liquid-repellent ability. Even though the SLIPS suffers from heavily physical damage, the surface can rapidly self-repair without any additional treatment and obtain slippery property again. The developed SLIPS promises to contribute to the achievement of omniphobic materials in self-cleaning, antifouling, biomedical devices, and fuel transport.
Co-reporter:Jiale Yong;Minjing Li;Qing Yang;Yao Fang;Jinglan Huo;Xun Hou
Journal of Materials Chemistry A 2017 vol. 5(Issue 48) pp:25249-25257
Publication Date(Web):2017/12/12
DOI:10.1039/C7TA07528F
A simple achievement of six different super-wettabilities on the femtosecond laser ablated polydimethylsiloxane (PDMS) surface is reported for the first time. Both the experimental and theoretical analysis revealed that underwater oil wettability and underwater bubbles' behavior on a solid surface are closely related to the in-air water wettability of the substrate surface. The original femtosecond laser-induced microstructured PDMS surface exhibited excellent superhydrophobicity in air and generally became superoleophilic and superaerophilic in water. After being further irradiated by oxygen plasma, the rough PDMS surface switched to superhydrophilic. Underwater superoleophobicity and superaerophobicity could be exhibited when such a superhydrophilic PDMS surface was immersed in water. Furthermore, various superhydrophobic–superhydrophilic, underwater superoleophobic–superoleophilic and underwater superaerophobic–superaerophilic hybrid patterns were successfully designed and achieved on the femtosecond laser ablated PDMS surface by subsequent selective oxygen plasma treatment. We believe that the reported preparation principle of superhydrophobic, superhydrophilic, underwater superoleophobic, underwater superoleophilic, underwater superaerophobic, and underwater superaerophilic surfaces would have important guiding significance to researchers and engineers to effectively control water droplets, oil droplets and the behavior of bubbles on a material surface.
Co-reporter:Jiale Yong;Qing Yang;Jinglan Huo;Xun Hou
Chemical Society Reviews 2017 vol. 46(Issue 14) pp:4168-4217
Publication Date(Web):2017/07/17
DOI:10.1039/C6CS00751A
Superoleophobicity is a phenomenon where the contact angles of various oil droplets with low surface tension on a solid surface are larger than 150°. In the past few years, there has been much growing interest in the design and application of superoleophobic surfaces. Such surfaces have great significance for both fundamental research and a variety of practical applications, including oil-repellent coatings, self-cleaning, oil/water separation, oil droplet manipulation, chemical shielding, anti-blocking, designing liquid microlens, oil capture, bioadhesion, guiding oil movement and floating on oil. Herein, we systematically summarize the recent developments of superoleophobic surfaces. This review focuses on the design, fabrication, characteristics, functions, and important applications of various superoleophobic surfaces. Although many significant advances have been achieved, superoleophobic surfaces are still in their “toddler stage” of development. The current challenges and future prospects of this fast-growing field of superoleophobicity are discussed.
Co-reporter:Zefang Deng;Qing Yang;Hao Bian;Guangqing Du;Jiale Yong;Chao Shan ;Xun Hou
Advanced Functional Materials 2016 Volume 26( Issue 12) pp:1995-2001
Publication Date(Web):
DOI:10.1002/adfm.201504941
The natural compound eye is a striking imaging device with a wealth of fascinating optical features such as a wide field of view (FOV), low aberration, and high sensitivity. Dragonflies in particular possess large, sophisticated compound eyes that exhibit high resolving power and information-processing capacity. Here, a large-scale artificial compound eye inspired by the unique designs of natural counterparts is presented. The artificial compound eye is created by a high-efficiency strategy that combines single-pulse femtosecond laser wet etching with thermal embossing. These eyes have a macrobase diameter of 5 mm and ≈30 000 close-packed ommatidia with an average diameter of 24.5 μm. Moreover, the optical properties of the artificial compound eyes are investigated; the results confirm that the eye demonstrates advanced imaging quality, an exceptionally wide FOV of up to 140°, and low aberration.
Co-reporter:Jiale Yong;Qing Yang;Hao Bian;Guangqing Du;Chao Shan;Jinglan Huo;Yao Fang ;Xun Hou
Advanced Materials Interfaces 2016 Volume 3( Issue 7) pp:
Publication Date(Web):
DOI:10.1002/admi.201500650
Co-reporter:Fei Wang, Chao Shan, Jian-ping Yan, Jiao Fu, D. Garuma Abdisa, Tian-fei Zhu, Wei Wang, Feng Chen, Jing-wen Zhang, Hong-Xing Wang, Xun Hou
Diamond and Related Materials 2016 Volume 63() pp:69-74
Publication Date(Web):March 2016
DOI:10.1016/j.diamond.2015.11.015
•We use femtosecond laser technique to form a non-diamond layer below diamond substrate.•Femtosecond laser processing could transfer diamond sp3 to graphite sp2.•Femtosecond laser technique has provided a potential way for the as-grown diamond film separation.In this paper, we report on an attempt to separate single crystal (SC) diamond film from diamond substrate by femtosecond laser treatment and electrochemical etching techniques. Firstly, femtosecond laser was focused on about 20 μm below the surface of diamond substrate to form a non-diamond layer. Secondly, a thick SC diamond film was grown on this substrate by microwave plasma chemical vapor deposition system. Finally, an electrochemical etching treatment was performed to separate the SC diamond film from its substrate. The results indicate that femtosecond laser technique has provided a potential way for the separation of grown diamond film from its substrate.
Co-reporter:Yu Lu, Qing Yang, Feng Chen, Guangqing Du, Yanmin Wu, Yan Ou, Xun Hou
Optics & Laser Technology 2016 Volume 77() pp:6-10
Publication Date(Web):March 2016
DOI:10.1016/j.optlastec.2015.07.017
•The electron dynamics model for exploring e-field enhancement was built.•The e-field spectrum with respect to electron excitation was obtained.•Near e-field tailoring on a nanorod via temporally shaped laser was predicted.The spatial–temporal dynamics of the near e-field enhancement in a resonance-mismatched nanorod irradiated by the femtosecond laser double pulses is theoretically investigated. A model combining the non-equilibrium electron excitation dynamics and the near field scattering was built for well exploring ultrafast dynamics of the e-field enhancement around the nanorod. It is revealed that the average enhancement factor can be evidently improved with increasing the double pulses separation. The energy ratio of the temporally shaped double pulses with respect to the highest enhancement factor shows an evident decrease with the increasing the total laser fluence. In addition, the most evident promotion of average enhancement factor from 51.2 to 78.8 can be acquired under laser fluence of 0.7Fth, which could be attributed to the temperature modulation of electron states excited by the temporally shaped double pulses. The study provides the base for understanding ultrafast plasmon dynamics for advancing the applications such as fs super-resolution fabrication, fs near field imaging and the generation of ultrashort extreme-ultraviolet pulses.
Co-reporter:Xiangwei Meng, Qing Yang, Feng Chen, Chao Shan, Keyin Liu, Yanyang Li, Hao Bian, Jinhai Si, Xun Hou
Optics & Laser Technology 2016 Volume 76() pp:29-32
Publication Date(Web):January 2016
DOI:10.1016/j.optlastec.2015.07.020
•3D solenoid multilayer microcoils with high uniformity were fabricated.•An alloy with high melting point was chosen as the conductive metal.•The multilayer microcoils with complex winding way were smartly controlled.•The inductance of microcoils was measured, quality factor was calculated.Three dimensional (3D) solenoid microcoils could generate uniform magnetic field. Multilayer solenoid microcoils are highly pursued for strong magnetic field and high inductance in advanced magnetic microsystems. However, the fabrication of the 3D multilayer solenoid microcoils is still a challenging task. In this paper, 3D multilayer solenoid microcoils with uniform diameters and high aspect ratio were fabricated in silica glass. An alloy (Bi/In/Sn/Pb) with high melting point was chosen as the conductive metal to overcome the limitation of working temperature and improve the electrical property. The inductance of the three layers microcoils was measured, and the value is 77.71 nH at 100 kHz and 17.39 nH at 120 MHz. The quality factor was calculated, and it has a value of 5.02 at 120 MHz. This approach shows an improvement method to achieve complex 3D metal microstructures and electronic components, which could be widely integrated in advanced magnetic microsystems.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Guangqing Du, Chao Shan, Hao Bian, Umar Farooq and Xun Hou
Journal of Materials Chemistry A 2015 vol. 3(Issue 18) pp:9379-9384
Publication Date(Web):18 Mar 2015
DOI:10.1039/C5TA01104C
Reported here is a bioinspired fabrication of transparent underwater superoleophobic and anti-oil surfaces using a femtosecond laser treatment. Rough nanoscale structures were readily created on silica glass surfaces by femtosecond laser-induced ablation. Underwater superoleophobicity and ultralow oil-adhesion were obtained by the rough nanostructures with a wide variation of processing parameters, and the as-prepared surfaces exhibited a high transparency in water. This phenomenon is attributed to the presence of the water environment because scattering and refraction are effectively weakened. As a maskless and cost-effective method, the femtosecond laser processing of transparent materials (glass) may provide a new method to create biomimetic transparent underwater surfaces, allowing for the development of novel underwater anti-oil optical devices.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Umar Farooq and Xun Hou
Journal of Materials Chemistry A 2015 vol. 3(Issue 20) pp:10703-10709
Publication Date(Web):21 Apr 2015
DOI:10.1039/C5TA01782C
Switchable underwater superoleophobicity–superoleophilicity on femtosecond laser-induced rough TiO2 surfaces by alternate UV irradiation and dark storage is achieved for the first time. Femtosecond laser ablation not only forms a micro/nanoscale hierarchical rough structure but also oxidizes the Ti materials, resulting in a rough TiO2 layer covering on the surface. The reversible switching of underwater oil wettability is caused by photoinduced switching between superhydrophobic and superhydrophilic states in air. These rough TiO2 surfaces can even respond to visible light. We believe this subtle switching method will be potentially applied in the biological and medical fields.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Yao Fang, Jinglan Huo and Xun Hou
Chemical Communications 2015 vol. 51(Issue 48) pp:9813-9816
Publication Date(Web):08 May 2015
DOI:10.1039/C5CC02939B
A simple and one-step method to form a rough ZnO layer consisting of micro/nanoscale hierarchical structures via direct femtosecond laser ablation of the Zn surface is reported for the first time. The resultant surfaces show switchable wettability between superhydrophobicity and quasi-superhydrophilicity via alternate UV irradiation and dark storage.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang and Xun Hou
Soft Matter 2015 vol. 11(Issue 46) pp:8897-8906
Publication Date(Web):22 Sep 2015
DOI:10.1039/C5SM02153G
Femtosecond laser microfabrication is emerging as a hot tool for controlling the wettability of solid surfaces. This paper introduces four typical aspects of femtosecond laser induced special wettability: superhydrophobicity, underwater superoleophobicity, anisotropic wettability, and smart wettability. The static properties are characterized by the contact angle measurement, while the dynamic features are investigated by the sliding behavior of a liquid droplet. Using different materials and machining methods results in different rough microstructures, patterns, and even chemistry on the solid substrates. So, various beautiful wettabilities can be realized because wettability is mainly dependent on the surface topography and chemical composition. The distinctions of the underlying formation mechanism of these wettabilities are also described in detail.
Co-reporter:Jiale Yong, Qing Yang, Feng Chen, Guangqing Du, Chao Shan, Umar Farooq, Jiuhong Wang and Xun Hou
RSC Advances 2015 vol. 5(Issue 51) pp:40907-40911
Publication Date(Web):10 Apr 2015
DOI:10.1039/C5RA04671H
This paper reports a new strategy to realize real liquid lens arrays without evaporation problems based on an underwater superoleophobic–oleophobic heterogeneous pattern. The flat circular region shows an inherent underwater oleophobicity while the femtosecond laser ablated region displays underwater superoleophobicity. In a water medium, the oil droplet is restricted to the untreated circle by the energy barrier at the superoleophobic–oleophobic boundary, thereby forming a convex lens shape by surface tension. The liquid lens array benefits from the surrounding water and then overcomes the problem of evaporation. The shape of the liquid lens can be simply controlled by the designed pattern and the oil volume.
Co-reporter:Jiale Yong;Qing Yang;Hao Bian;Guangqing Du;Umar Farooq ;Xun Hou
Advanced Materials Interfaces 2015 Volume 2( Issue 2) pp:
Publication Date(Web):
DOI:10.1002/admi.201400388
Co-reporter:Yu Lu;Qing Yang;Guangqing Du;Yanmin Wu;Yan Ou;Jinhai Si
Plasmonics 2015 Volume 10( Issue 6) pp:1325-1330
Publication Date(Web):2015 December
DOI:10.1007/s11468-015-9939-9
The localized electric field enhancement of Au-Ag nanorods dimer is theoretically investigated based on finite element method (FEM). An analytical mutual-interference model between asymmetric dipole-dimer has been built to describe the dipoles coupling with different resonance modes in heterogeneous dimer. Three prominent enhancement peaks could be observed from ultraviolet to visible spectrum, in which the ultraviolet resonance especially corresponds to a higher mode in both Ag and Au nanorods. The results reveal the strong coupling mechanism among different dipoles existing in the asymmetric dipole system, which could support the design of plasmonic nanodevices in larger resonance wavelength range.
Co-reporter:Keyin Liu;Qing Yang;Yulong Zhao
Microfluidics and Nanofluidics 2015 Volume 19( Issue 1) pp:169-180
Publication Date(Web):2015 July
DOI:10.1007/s10404-015-1558-4
We demonstrated rapid and stable fluid micromixing at low Reynolds numbers in an easily fabricated and geometrically simple three-dimensional cross-linked dual helical (CLDH) micromixer. Mixing mechanism of the CLDH channels was investigated with numerical simulations. The split and recombine (SAR), chaotic advection, and flow impact mixing effects were integrated and improved in the passive mixer with CLDH channels.
A new SAR mixing effect dominated by flow collision was involved in the mixer in which a cycle of CLDH mixer can achieve two SAR mixing courses which is more effective than conventional SAR mixers. A geometric optimization method of studying the mass flow rate of flow streams was proposed to obtain the optimized structure, which can be applied to optimizing passive mixers with crossed or overlapped channels. The CLDH mixer shows a stable and excellent mixing capability in an extra short length for a wide low Re range; 99 % mixing degree can be achieved in four cycles (i.e., 320 μm) for 0.003 < Re < 30. This rapid and robust micromixer will contribute to a flexible application in microfluidic systems.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Dongshi Zhang, Umar Farooq, Guangqing Du and Xun Hou
Journal of Materials Chemistry A 2014 vol. 2(Issue 23) pp:8790-8795
Publication Date(Web):09 Apr 2014
DOI:10.1039/C4TA01277A
Femtosecond laser microfabrication has been recently utilized in interface science to modify the liquid wettability of solid surfaces. In this paper, a silicon surface with hierarchical micro/nanostructure is fabricated by a femtosecond laser. Similar to fish scales, the laser-induced surface shows superhydrophilicity in air and superoleophobicity underwater. The oil contact angles can reach up to 159.4 ± 1° and 150.3 ± 2°, respectively, for 1,2-dichloroethane and chloroform droplets in water. In addition, the surface exhibits ultralow oil-adhesion. In the oil–water–solid three-phase system, water can be trapped in the hierarchical rough structure and form a repulsive oil layer according to the extended Cassie's theory. The contact area between the as-prepared surface and oil droplets is significantly reduced, resulting in superoleophobicity and ultralow oil-adhesion in water. In addition, as a potential application, the working principle diagram of preventing blockage ability of underwater superoleophobic pipes is propounded.
Co-reporter:Jiale Yong, Qing Yang, Feng Chen, Dongshi Zhang, Umar Farooq, Guangqing Du and Xun Hou
Journal of Materials Chemistry A 2014 vol. 2(Issue 15) pp:5499-5507
Publication Date(Web):21 Jan 2014
DOI:10.1039/C3TA14711H
The superhydrophobicity, controllable water adhesion, anisotropic sliding, and anisotropic wetting, which are four typical aspects of the wettability of solid surfaces, have attracted much interest in fundamental research and practical applications. However, how to use a simple and effective method to realize all those properties is still a huge challenge. Here, we present a method to realize periodic line-patterned polydimethylsiloxane (PDMS) surfaces by a femtosecond laser simply and efficiently. By adjusting the period (D) or average distance of adjacent microgrooves, the as-prepared surfaces can exhibit superhydrophobicity, controllable water adhesion, anisotropic sliding, and anisotropic wetting. We believe that these multifunctional surfaces have enormous potential applications in novel microfluidic devices, microdroplet manipulation, liquid microdroplet directional transfer, and lab-on-chips.
Co-reporter:Jiale Yong, Qing Yang, Feng Chen, Dongshi Zhang, Guangqing Du, Hao Bian, Jinhai Si and Xun Hou
RSC Advances 2014 vol. 4(Issue 16) pp:8138-8143
Publication Date(Web):14 Jan 2014
DOI:10.1039/C3RA46929H
Butterfly wings have the ability to directionally control the movement of water microdroplets. However, the realization of artificial directional sliding biosurfaces has remained challenging. Inspired by butterfly wings, a new kind of directional patterned surface is developed to achieve superhydrophobicity and anisotropic adhesive properties at the one-dimensional level. The surface is composed of a hydrophobic triangle array and surrounding superhydrophobic structure. On the as-prepared surface, a droplet rolls along one direction distinctly easier than its opposite direction. The maximum anisotropy of sliding angles along two opposite directions can reach 21°. This unique ability is ascribed to the direction-dependent arrangement of the two-dimensional (2D) triangle array patterns. The directional adhesive superhydrophobic surfaces could be potentially applied in novel microfluid-controllable devices and directional easy-cleaning coatings.
Co-reporter:Yang Hu, Qing Yang, Feng Chen, Hao Bian, Zefang Deng, Guangqing Du, Jinhai Si, Feng Yun, Xun Hou
Applied Surface Science 2014 Volume 292() pp:285-290
Publication Date(Web):15 February 2014
DOI:10.1016/j.apsusc.2013.11.132
Highlights
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This paper presents a cost-efficient and flexible approach to fabricate rectangular-shaped microlens arrays with controllable aspect ratio and spherical morphology.
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The aspect ratio of rectangular-shaped microlens arrays can be controlled within a certain range from 2:1 to 1:1.
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The rectangular-shaped microlens arrays have excellent spherical morphology.
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More than 10,000 rectangular-shaped microlens with high fill factor can be manufactured in a few hours.
Co-reporter:Jiale Yong, Qing Yang, Feng Chen, Dongshi Zhang, Guangqing Du, Hao Bian, Jinhai Si, Feng Yun, Xun Hou
Applied Surface Science 2014 Volume 288() pp:579-583
Publication Date(Web):1 January 2014
DOI:10.1016/j.apsusc.2013.10.076
Highlights
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The 3D pattern-structured superhydrophobic surfaces were fabricated.
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Different 3D patterns give rise to different water adhesion.
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The adhesion of designed surfaces can be tuned from ultralow to ultrahigh.
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The adhesion controllability is ascribed to the distinct contact modes.
Co-reporter:Guangqing Du, Feng Chen, Qing Yang, Yan Ou, Yanmin Wu, Yu Lu, Hao Bian, Xun Hou
Chemical Physics Letters 2014 Volume 597() pp:153-157
Publication Date(Web):28 March 2014
DOI:10.1016/j.cplett.2014.02.035
Highlights
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The non-equilibrium thermal dynamics is proposed for explaining nano-grating formation.
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The electron diffusion and electron–phonon coupling are competitive for regulating nano-grating contrast.
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The synergetic effects arising from pulse-to-pulse relevance can explain nano-grating contrast modulations.
Co-reporter:Keyin Liu, Qing Yang, Yulong Zhao, Feng Chen, Chao Shan, Shengguan He, Xiaole Fan, Lei li, Xiangwei Meng, Guangqing Du, Hao Bian
Microelectronic Engineering 2014 Volume 113() pp:93-97
Publication Date(Web):January 2014
DOI:10.1016/j.mee.2013.07.017
•True-3D metallic microcomponents were fabricated.•3D micromoulds in fused silica were fabricated by the femtosecond laser.•3D metallic microstructures were achieved by injecting liquid metal into the moulds.•A microfluidic-compatible micromoulding device was used.•The 3D metallic microcomponents can be conveniently applied in microfluidic.Three-dimensional (3D) metallic microdevices have attracted a wide attention in the field of functional microsystems, but the fabrication of 3D metallic structures remains a technical challenge. In this study, a femtosecond-laser-based microsolidifying method was employed to fabricate 3D metallic structures by injecting liquid metal into complex 3D microchannels/cavities in fused silica and solidifying the liquid metal. 3D microchannels/cavities, which were served as micromoulds of the metallic microcomponents, were fabricated in fused silica by taking full advantage of the improved femtosecond laser irradiation followed by chemical etching (FLICE) technology. A PDMS-glass injection device was employed to finish the injection of liquid metal and solidification process. This technology will enable the maskless and facile fabrication of complex true-3D metallic conductive microcomponents for a wide array of micro-applications.
Co-reporter:Feng Chen, Dongshi Zhang, Qing Yang, Jiale Yong, Guangqing Du, Jinhai Si, Feng Yun, and Xun Hou
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 15) pp:6777
Publication Date(Web):July 18, 2013
DOI:10.1021/am401677z
Bioinspired special wettibilities including superhydrophobicity and tunable adhesive force have drawn considerable attention because of their significant potential for fundamental research and practical applications. This review summarizes recent progress in the development of bioinspired wetting surfaces via laser microfabrication, with a focus on controllable, biomimetic, and switchable wetting surfaces, as well as their applications in biology, microfluidic, and paper-based devices, all of which demonstrate the ability of laser microfabrication in producing various multiscale structures and its adaptation in a great variety of materials. In particular, compared to other techniques, laser microfabrication can realize special modulation ranging from superhydrophilic to superhydrophobic without the assistance of fluorination, allowing much more freedom to achieve complex multiple-wettability integration. The current challenges and future research prospects of this rapidly developing field are also being discussed. These approaches open the intriguing possibility of the development of advanced interfaces equipped with the integration of more functionalities.Keywords: bioinspired surface; biomemetic surface; hierarchical structures; laser microfabrication; switchable wetting surface;
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Guangqing Du, Hao Bian, Dongshi Zhang, Jinhai Si, Feng Yun, and Xun Hou
ACS Applied Materials & Interfaces 2013 Volume 5(Issue 19) pp:9382
Publication Date(Web):September 13, 2013
DOI:10.1021/am402923t
A fast and single-step process is developed for the fabrication of low-cost, high-quality, and large-area concave microlens arrays (MLAs) by the high-speed line-scanning of femtosecond laser pulses. Each concave microlens can be generated by a single laser pulse, and over 2.78 million microlenses were fabricated on a 2 × 2 cm2 polydimethylsiloxane (PDMS) sheet within 50 min, which greatly enhances the processing efficiency compared to the classical laser direct writing method. The mechanical pressure induced by the expansion of the laser-induced plasmas as well as a long resolidifing time is the reason for the formation of smooth concave spherical microstructures. We show that uniform microlenses with different diameters and depths can be controlled by adjusting the power of laser pulses. Their high-quality optical performance is also demonstrated in this work.Keywords: concave microlens array; femtosecond laser; optical performance; single pulse ablation;
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Dongshi Zhang, Guangqing Du, Jinhai Si, Feng Yun, and Xun Hou
The Journal of Physical Chemistry C 2013 Volume 117(Issue 47) pp:24907-24912
Publication Date(Web):November 7, 2013
DOI:10.1021/jp408863u
We present a rapid, facile, and simple method to realize superhydrophobic patterned polydimethylsiloxane (PDMS) surfaces with tunable adhesion by a femtosecond laser. These surfaces are composed of superhydrophobic laser-induced structures and hydrophobic unstructured square array. The femtosecond laser structured domain shows superhydrophobicity with ultralow water adhesion, while the nonstructured flat PDMS shows ordinary hydrophobicity with ultrahigh water adhesion. By adjusting the relative area fraction of laser structured and nonstructured domains, the as-prepared superhydrophobic surfaces show tunable water adhesion that ranges from ultralow to ultrahigh, on which the sliding angle can be controlled from 1° to 90° (a water droplet cannot slide down even when the as-prepared surface is vertical or turned upside down). The tunable adhesive superhydrophobic surfaces achieved by femtosecond laser microfabrication may be potentially used in microfluidic systems to modulate the mobility of liquid droplets.
Co-reporter:Hao Bian, Qing Yang, Hewei Liu, Feng Chen, Guangqing Du, Jinhai Si, Xun Hou
Materials Science and Engineering: C 2013 Volume 33(Issue 2) pp:663-667
Publication Date(Web):1 March 2013
DOI:10.1016/j.msec.2012.10.014
Netlike or porous microstructures are highly desirable in metal implants and biomedical monitoring applications. However, realization of such microstructures remains technically challenging. Here, we report a facile and environmentally friendly method to prepare netlike microstructures on a stainless steel by taking the full advantage of the liquid-mediated femtosecond laser ablation. An unordered netlike structure and a quasi-ordered array of holes can be fabricated on the surface of stainless steel via an ethanol-mediated femtosecond laser line-scan method. SEM analysis of the surface morphology indicates that the porous netlike structure is in the micrometer scale and the diameter of the quasi-ordered holes ranges from 280 nm to 320 nm. Besides, we find that the obtained structures are tunable by altering the laser processing parameters especially scanning speed.Highlights► A fabrication method of an unordered netlike structure and a quasi-ordered array of holes on metallic surface is developed. ► The porous netlike structure is in the micrometer scale. ► The diameter of the quasi-ordered holes ranges from 280 nm to 320 nm. ► The obtained structures are tunable by altering the laser scanning speed.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Dongshi Zhang, Hao Bian, Guangqing Du, Jinhai Si, Xiangwei Meng, and Xun Hou
Langmuir 2013 Volume 29(Issue 10) pp:3274-3279
Publication Date(Web):February 6, 2013
DOI:10.1021/la304492c
This paper presents a one-step method to fabricate superhydrophobic surfaces with extremely controllable adhesion based on PDMS microwell arrays. The microwell array structures are rapidly produced on PDMS films by a point-by-point femtosecond laser scanning process. The as-prepared superhydrophobic surfaces show water controllable adhesion that ranges from ultrahigh to ultralow by adjusting the extent of overlap of the adjacent microwells, on which the sliding angle can be controlled from 180° (a water droplet can not slide down even when the as-prepared surface is turned upside down) to 3°. A “micro-airbag effect” is introduced to explain the adhesion transition phenomenon of the microwell array structures. This work provides a facile and promising strategy to fabricate superhydrophobic surfaces with controllable adhesion.
Co-reporter:Hao Bian, Qing Yang, Feng Chen, Hewei Liu, Guangqing Du, Zefang Deng, Jinhai Si, Feng Yun, Xun Hou
Materials Science and Engineering: C 2013 Volume 33(Issue 5) pp:2795-2799
Publication Date(Web):1 July 2013
DOI:10.1016/j.msec.2013.02.048
•We demonstrate a flexible method to fabricate curvilinear microstructures.•This method composes of femtosecond laser exposures and chemical etching process.•Concave microstructures with different profiles were fabricated on silica glasses.•High-quality microlens arrays and high-aspect-ratio microwells were fabricated.Materials with curvilinear surface microstructures are highly desirable for micro-optical and biomedical devices. However, realization of such devices efficiently remains technically challenging. This paper demonstrates a facile and flexible method to fabricate curvilinear microstructures with controllable shapes and dimensions. The method composes of femtosecond laser exposures and chemical etching process with the hydrofluoric acid solutions. By fixed-point and step-in laser irradiations followed by the chemical treatments, concave microstructures with different profiles such as spherical, conical, bell-like and parabola were fabricated on silica glasses. The convex structures were replicated on polymers by the casting replication process. In this work, we used this technique to fabricate high-quality microlens arrays and high-aspect-ratio microwells which can be used in 3D cell culture. This approach offers several advantages such as high-efficient, scalable shape-controllable and easy manipulations.
Co-reporter:Keyin Liu;Qing Yang;Shengguan He;Yulong Zhao
Microsystem Technologies 2013 Volume 19( Issue 7) pp:1033-1040
Publication Date(Web):2013 July
DOI:10.1007/s00542-012-1695-6
True three-dimensional (3D) micromixers in fused silica are highly desirable for efficient and compact mixing in microfluidic applications. However, realization of such devices remains technically challenging. Here, we report high-quality fabrication of 3D helical microchannels in fused silica by taking the full advantage of an improved femtosecond laser irradiation followed by chemical etching process, and a glass-PDMS interface structure is introduced for assembling 3D helical micromixer. Highly efficient mixing is achieved in the helical micromixer at low Reynolds numbers, whose excellent mixing performance is approved by the experimental evaluation and computational fluid dynamics simulation.
Co-reporter:Dongshi Zhang, Feng Chen, Qing Yang, Jiale Yong, Hao Bian, Yan Ou, Jinhai Si, Xiangwei Meng, and Xun Hou
ACS Applied Materials & Interfaces 2012 Volume 4(Issue 9) pp:4905
Publication Date(Web):August 21, 2012
DOI:10.1021/am3012388
In this paper, we present a new approach to the tunable adhesive superhydrophobic surfaces consisting of periodic hydrophobic patterns and superhydrophobic structures by femtosecond (fs) laser irradiation on silicon. The surfaces are composed of periodic hydrophobic patterns (triangle, circle, and rhombus) and superhydrophobic structures (dual-scale spikes induced by a fs laser). Our results reveal that the adhesive forces of as-prepared surfaces can be tuned by varying the area ratio (ARs-h) of superhydrophobic domain to hydrophobic domain, thus resulting in tunable static and dynamic wettabilities. By increasing ARs-h, (i) the static wetting property, which is characterized by the minimum water droplet volume that enables a droplet to land on the surface, can be tailored from 1 μL to 9 μL; (ii) the sliding angle can be flexibly adjusted, ranging from >90° (a droplet cannot slide off when the sample is positioned upside down) to 5°; and (iii) the droplet rebound behaviors can be modulated from partial rebound to triple rebound. In addition, the Cassie–Baxter model and the sliding angle model are used to speculate the contact angles and sliding angles to provide potentially theoretical models to design slippery-to-sticky superhydrophobic surfaces. The tunable adhesive superhydrophobic surfaces achieved by fs laser microfabrication may be potentially used in microfluidic systems to modulate the mobility of liquid droplets.Keywords: femtosecond laser; silicon spikes; superhydrophobic surface; superhydrophobic−hydrophobic pattern; tunable wettability; water drop rebound;
Co-reporter:Dongshi Zhang, Feng Chen, Qing Yang, Jinhai Si and Xun Hou
Soft Matter 2011 vol. 7(Issue 18) pp:8337-8342
Publication Date(Web):08 Aug 2011
DOI:10.1039/C1SM05649B
This paper reports on the mutual wetting transitions between anisotropic and isotropic on directional structures fabricated by femtosecond (fs) laser. The directional structures are composed of flat Si triangular patterns and fs laser induced spikes. After chemical deposition of a layer of fluoroalkylsilane, the triangular areas and periodic spikes exhibited hydrophobicity and superhydrophobicity, respectively. With increasing water volume, the droplet experienced a series of mutual wetting transitions due to the stick-jump behaviors of triple-phase contact line in orthogonal directions. The typical dynamic triple-phase contact line behaviors were quantitatively analyzed, based on which the specific energy barriers exerted by triangular patterns were speculated. A two-strip model was introduced to explain the reason of mutual wetting transitions.
Co-reporter:Guangqing Du, Qing Yang, Feng Chen, Jinhai Si, Xun Hou
Applied Surface Science 2011 Volume 257(Issue 21) pp:9177-9182
Publication Date(Web):15 August 2011
DOI:10.1016/j.apsusc.2011.05.128
Abstract
We theoretically investigated different thermal relaxation participating in the ultrafast thermionic emission processes on gold film surface with a femtosecond pulse excitation. The thermionic emission regimes under the two temperature relaxation and the thermal diffusion relaxation were demonstrated. The simulations showed that the thermionic emission properties can be defined in the regime under two temperature relaxation by reducing the laser fluence, or widening the pulse duration or increasing the laser wavelength. It was also found that there exists a transition between the two distinct thermionic emission regimes under peculiar laser parameters of laser fluence, pulse duration and laser wavelength. The results were explained as significant intervene of laser irradiation parameters into gold film thermal relaxation processes.
Co-reporter:Guangqing Du, Feng Chen, Qing Yang, Jinhai Si, Xun Hou
Optics Communications 2011 Volume 284(Issue 2) pp:640-645
Publication Date(Web):15 January 2011
DOI:10.1016/j.optcom.2010.09.061
Co-reporter:Xianhua Wang, Feng Chen, Hewei Liu, Weiwei Liang, Qing Yang, Jinhai Si, Xun Hou
Optics Communications 2011 Volume 284(Issue 1) pp:317-321
Publication Date(Web):1 January 2011
DOI:10.1016/j.optcom.2010.08.039
By femtosecond laser line-by-line scanning irradiating, large-scale microstructures were formed on the surface of silicon with dimensions of 1 × 1 mm2. Scanning electron microscope investigations exhibited that homogeneous surface microstructures, such as directional-arranged bacilliform mesoporous structures, have been successfully prepared. The dependence of the surface morphology on laser pulse energy was analyzed, and the results indicated that the bacilliform mesoporous structures only can be textured within a certain energy range. The optical reflective spectrum measurement revealed that the presence of bacilliform mesoporous structures can significantly enhance the absorptivity of silicon at visible light range. This work would help to control the formation of surface micro/nanostructures on silicon and other materials, which has potential applications in solar energy, photoelectronics, biology and material science.
Co-reporter:Feng Chen, Dongshi Zhang, Qing Yang, Xianhua Wang, Baojiang Dai, Xiangming Li, Xiuqing Hao, Yucheng Ding, Jinhai Si, and Xun Hou
Langmuir 2011 Volume 27(Issue 1) pp:359-365
Publication Date(Web):December 9, 2010
DOI:10.1021/la103293j
In this paper, we present a new method to realize anisotropy by restricting a droplet on an unstructured Si hydrophobic domain between two superhydrophobic strips fabricated by femtosecond laser. The water contact angles and corresponding water baseline length were investigated. The results showed that anisotropy would vary with the volume-induced pinning−depinning−repinning behavior of the droplet. Furthermore, through the observation of water response on small Si domain, the adhesive force of the structure is proven to be the key factor giving rise to the anisotropy wetting. This phenomenon could potentially be used as a model for fundamental research, and such structures could be utilized to control large volume in microfluidic devices, lab-on-chip system, microreactors, and self-cleaning surfaces.
Co-reporter:Weiwei Liang, Feng Chen, Hao Bian, Qing Yang, Hewei Liu, Xianhua Wang, Jinhai Si, Xun Hou
Optics Communications 2010 Volume 283(Issue 11) pp:2385-2389
Publication Date(Web):1 June 2010
DOI:10.1016/j.optcom.2010.02.003
Periodic surface nanostructures induced by femtosecond laser pulses on polycrystalline ZnO are presented. By translating the sample line-by-line under appropriate irradiation conditions, grating-like nanostructures with an average period of 160 nm are fabricated. The dependence of surface morphologies on the processing parameters, such as laser fluence, pulse number and laser polarization, are studied by scanning electronic microscope (SEM). In addition, photoluminescence (PL) analysis at room-temperature indicates that the PL intensity of the irradiated area increases significantly compared with the un-irradiated area. Using femtosecond laser pulses irradiation to fabricate periodic surface nanostructures on polycrystalline ZnO is efficient, simple and low cost, which shows great potential applications in ZnO-based optoelectronic devices.
Co-reporter:Hewei Liu, Feng Chen, Xianhua Wang, Qing Yang, Hao Bian, Jinhai Si, Xun Hou
Thin Solid Films 2010 Volume 518(Issue 18) pp:5188-5194
Publication Date(Web):1 July 2010
DOI:10.1016/j.tsf.2010.04.043
Liquid-assisted ablation of solids by femtosecond laser pulses has proved to be an efficient tool for highly precise microfabrication, which evokes numerous research interests in recent years. In this paper, we systematically investigate the interaction of femtosecond laser pulses with silicon wafer in water, alcohol, and as a comparison, in air. After producing a series of multiple-shot craters on a silicon wafer in the three types of environments, surface morphologies and femtosecond laser-induced periodic surface structures are comparatively studied via the scanning electron microscope investigations. Meanwhile, the influence of liquid mediums on ablation threshold fluence and ablation depth is also numerically analyzed. The experimental results indicate that the ablation threshold fluences of silicon are reduced by the presence of liquids (water/alcohol) and ablation depths of craters are deepened in ambient water. Furthermore, smoother surfaces tend to be obtained in alcohol-mediated ablation at smaller shot numbers. Finally, the evolution of the femtosecond laser-induced periodic surface structures in air, water and alcohol is also discussed.
Co-reporter:DongShi Zhang;HeWei Liu;XianHua Wang;Kai Du
Science Bulletin 2010 Volume 55( Issue 9) pp:877-881
Publication Date(Web):2010 March
DOI:10.1007/s11434-009-0550-3
Aiming at fabrication of complex microstructures and micro-patterns, a kind of femtosecond laser micromachining technology based on the BMP image edge tracing was proposed. We introduced the general principle of this technology and discussed the implementation of the machining paths extraction, optimization, tracing and the feedback of the machining procession in detail. On the basis of this technology, control software for femtosecond laser micromachining was developed. Furthermore, we have accomplished the fabrication of complicated two-dimensional (2D) micro-patterns on a copper thin film. The results indicate that this technology can be used for digital control micromachining of complex patterns or microstructures at micron and submicron scales by femtosecond laser.
Co-reporter:Hewei Liu, Feng Chen, Xianhua Wang, Qing Yang, Dongshi Zhang, Jinhai Si, Xun Hou
Optics Communications 2009 Volume 282(Issue 20) pp:4119-4123
Publication Date(Web):15 October 2009
DOI:10.1016/j.optcom.2009.07.017
We fabricated spherical microlenses on optical glasses by femtosecond laser direct writing (FLDW) in ambient air. To achieve good appearances of the microlenses, a meridian-arcs scanning method was used after a selective multilayer removal process with spiral scanning paths. A positive spherical microlens with diameter of 48 μm and height of 13.2 μm was fabricated on the surface of the glass substrate. The optical performances of the microlens were also tested. Compared to the conventional laser direct writing (LDW) technique, this work could provide an effective method for precise shape-controlled fabrication of three-dimensional (3D) microstructures with curved surfaces on difficult-to-cut materials for practical applications.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Jinglan Huo and Xun Hou
Chemical Society Reviews 2017 - vol. 46(Issue 14) pp:NaN4217-4217
Publication Date(Web):2017/05/02
DOI:10.1039/C6CS00751A
Superoleophobicity is a phenomenon where the contact angles of various oil droplets with low surface tension on a solid surface are larger than 150°. In the past few years, there has been much growing interest in the design and application of superoleophobic surfaces. Such surfaces have great significance for both fundamental research and a variety of practical applications, including oil-repellent coatings, self-cleaning, oil/water separation, oil droplet manipulation, chemical shielding, anti-blocking, designing liquid microlens, oil capture, bioadhesion, guiding oil movement and floating on oil. Herein, we systematically summarize the recent developments of superoleophobic surfaces. This review focuses on the design, fabrication, characteristics, functions, and important applications of various superoleophobic surfaces. Although many significant advances have been achieved, superoleophobic surfaces are still in their “toddler stage” of development. The current challenges and future prospects of this fast-growing field of superoleophobicity are discussed.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Yao Fang, Jinglan Huo and Xun Hou
Chemical Communications 2015 - vol. 51(Issue 48) pp:NaN9816-9816
Publication Date(Web):2015/05/08
DOI:10.1039/C5CC02939B
A simple and one-step method to form a rough ZnO layer consisting of micro/nanoscale hierarchical structures via direct femtosecond laser ablation of the Zn surface is reported for the first time. The resultant surfaces show switchable wettability between superhydrophobicity and quasi-superhydrophilicity via alternate UV irradiation and dark storage.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Umar Farooq and Xun Hou
Journal of Materials Chemistry A 2015 - vol. 3(Issue 20) pp:NaN10709-10709
Publication Date(Web):2015/04/21
DOI:10.1039/C5TA01782C
Switchable underwater superoleophobicity–superoleophilicity on femtosecond laser-induced rough TiO2 surfaces by alternate UV irradiation and dark storage is achieved for the first time. Femtosecond laser ablation not only forms a micro/nanoscale hierarchical rough structure but also oxidizes the Ti materials, resulting in a rough TiO2 layer covering on the surface. The reversible switching of underwater oil wettability is caused by photoinduced switching between superhydrophobic and superhydrophilic states in air. These rough TiO2 surfaces can even respond to visible light. We believe this subtle switching method will be potentially applied in the biological and medical fields.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Dongshi Zhang, Umar Farooq, Guangqing Du and Xun Hou
Journal of Materials Chemistry A 2014 - vol. 2(Issue 23) pp:NaN8795-8795
Publication Date(Web):2014/04/09
DOI:10.1039/C4TA01277A
Femtosecond laser microfabrication has been recently utilized in interface science to modify the liquid wettability of solid surfaces. In this paper, a silicon surface with hierarchical micro/nanostructure is fabricated by a femtosecond laser. Similar to fish scales, the laser-induced surface shows superhydrophilicity in air and superoleophobicity underwater. The oil contact angles can reach up to 159.4 ± 1° and 150.3 ± 2°, respectively, for 1,2-dichloroethane and chloroform droplets in water. In addition, the surface exhibits ultralow oil-adhesion. In the oil–water–solid three-phase system, water can be trapped in the hierarchical rough structure and form a repulsive oil layer according to the extended Cassie's theory. The contact area between the as-prepared surface and oil droplets is significantly reduced, resulting in superoleophobicity and ultralow oil-adhesion in water. In addition, as a potential application, the working principle diagram of preventing blockage ability of underwater superoleophobic pipes is propounded.
Co-reporter:Jiale Yong, Qing Yang, Feng Chen, Dongshi Zhang, Umar Farooq, Guangqing Du and Xun Hou
Journal of Materials Chemistry A 2014 - vol. 2(Issue 15) pp:NaN5507-5507
Publication Date(Web):2014/01/21
DOI:10.1039/C3TA14711H
The superhydrophobicity, controllable water adhesion, anisotropic sliding, and anisotropic wetting, which are four typical aspects of the wettability of solid surfaces, have attracted much interest in fundamental research and practical applications. However, how to use a simple and effective method to realize all those properties is still a huge challenge. Here, we present a method to realize periodic line-patterned polydimethylsiloxane (PDMS) surfaces by a femtosecond laser simply and efficiently. By adjusting the period (D) or average distance of adjacent microgrooves, the as-prepared surfaces can exhibit superhydrophobicity, controllable water adhesion, anisotropic sliding, and anisotropic wetting. We believe that these multifunctional surfaces have enormous potential applications in novel microfluidic devices, microdroplet manipulation, liquid microdroplet directional transfer, and lab-on-chips.
Co-reporter:Jiale Yong, Feng Chen, Qing Yang, Guangqing Du, Chao Shan, Hao Bian, Umar Farooq and Xun Hou
Journal of Materials Chemistry A 2015 - vol. 3(Issue 18) pp:NaN9384-9384
Publication Date(Web):2015/03/18
DOI:10.1039/C5TA01104C
Reported here is a bioinspired fabrication of transparent underwater superoleophobic and anti-oil surfaces using a femtosecond laser treatment. Rough nanoscale structures were readily created on silica glass surfaces by femtosecond laser-induced ablation. Underwater superoleophobicity and ultralow oil-adhesion were obtained by the rough nanostructures with a wide variation of processing parameters, and the as-prepared surfaces exhibited a high transparency in water. This phenomenon is attributed to the presence of the water environment because scattering and refraction are effectively weakened. As a maskless and cost-effective method, the femtosecond laser processing of transparent materials (glass) may provide a new method to create biomimetic transparent underwater surfaces, allowing for the development of novel underwater anti-oil optical devices.
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