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1.
Photocontrolled surfaces have attracted increasing interest because of their potential applications in lithography, photopatterning, biointerfaces, and microfluidics. Light provides high spatiotemporal resolution to control functions of such surfaces without getting into direct contact. However, conventional photocontrolled surfaces can only be switched between two states (on and off). The development of photocontrolled reconfigurable surfaces that can be switched among multiple states is highly desirable because these surfaces can adapt to rapid environmental changes or different applications. Herein, recent developments of photocontrolled reconfigurable surfaces are reviewed. Specially, reconfigurable surfaces based on photocontrolled reversible reactions including thiol‐quinone methide, disulfide exchange, thiol‐disulfide interconversion, diselenide exchange, and photosubstitution of Ru complexes are highlighted. As a perspective, other photocontrolled dynamic bonds that can be used to construct reconfigurable surfaces are summarized. Remaining challenges in this field are discussed. 相似文献
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William S. Y. Wong Philipp Gutruf Sharath Sriram Madhu Bhaskaran Zuankai Wang Antonio Tricoli 《Advanced functional materials》2016,26(3):399-407
Engineering surfaces that enable the dynamic tuning of their wetting state is critical to many applications including integrated microfluidics systems, flexible electronics, and smart fabrics. Despite extensive progress, most of the switchable surfaces reported are based on ordered structures that suffer from poor scalability and high fabrication costs. Here, a robust and facile bottom‐up approach is demonstrated that allows for the dynamical and reversible switching between lotus leaf (repulsive) and rose petal (adhesive) states by strain engineering of wave‐like nanofiber layers. Interestingly, it is found that the controlled switching between these two distinctive states is sensitive to the shape of the nanofibers. Moreover, it is observed that the structural integrity of the nanofibers is fully preserved during multicycle dynamic switching. The application of these optimal structures is showcased as mechanical hands demonstrating the capture of water microdroplets and their subsequent release in a well‐controlled manner. It is envisioned that this low‐cost and highly scalable surface texture is a powerful platform for the design of portable microfluidics systems, and the fabrication of large‐scale devices for ambient humidity harvesting and water purification. 相似文献
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Johannes M. Scheiger Shuai Li Marius Brehm Andreas Bartschat Patrick Theato Pavel A. Levkin 《Advanced functional materials》2021,31(49):2105681
Organogels (hydrophobic polymer gels) are soft materials based on polymeric networks swollen in organic solvents. They are hydrophobic and possess a high content of solvent and low surface adhesion, rendering them interesting in applications such as encapsulants, drug delivery, actuators, slippery surfaces (self-cleaning, anti-waxing, anti-bacterial), or for oil-water separation. To design functional organogels, strategies to control their shape and surface structure are required. Herein, the inherent UV photodegradability of poly(methacrylate) organogels is reported. No additional photosensitizers are required to efficiently degrade organogels (d ≈ 1 mm) on the minute scale. A low UV absorbance and a high swelling ability of the solvent infusing the organogel are found to be beneficial for fast photodegradation, which is expected to be transferrable to other gel photochemistry. Organogel arrays, films, and structured organogel surfaces are prepared, and their extraction ability and slippery properties are examined. Films of inherently photodegradable organogels on copper circuit boards serve as the first ever positive gel photoresist. Spatially photodegraded organogel films protect or reveal copper surfaces against an etchant (FeCl3 aq.). 相似文献
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Vahid Nasirimarekani Fernando Benito-Lopez Lourdes Basabe-Desmonts 《Advanced functional materials》2021,31(32):2100178
The manipulation of droplets via a magnetic field forms the basis of a fascinating technology that is currently in development. Often, the movement of droplets with magnets involves adding magnetic particles in or around the droplet; alternatively, magneto responsive surfaces may also be used. This work, presents and characterizes experimentally the formation and properties of a tunable superparamagnetic ring (tSPRing), which precisely adjusts itself around a water droplet, due to liquid–liquid interaction, and enables the physical manipulation of droplets. The ring is made of an oil-based ferrofluid, a stable suspension of ferromagnetic particles in an oily phase. It appears spontaneously due to the oil–water interfacial interaction under the influence of a magnetic field. The ferrofluid–water interaction resembles a cupcake assembly, with the surrounding ring only at the base of the droplet. The ring is analogous to a soft matter ring magnet, showing dipole repulsive forces, which stabilizes the droplets on a surface. It enables robust, controllable, and programmable manipulation of enclosed water droplets. This work opens the door to new applications in open surface upside or upside-down microfluidics and lays the groundwork for new studies on tunable interfaces between two immiscible liquids. 相似文献
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Haiyang Zhan Yuhang Xia Yihe Liu Haojie Sun Wenna Ge Shile Feng Yahua Liu 《Advanced functional materials》2023,33(9):2211317
Designing intelligent slippery surfaces for droplet manipulation is critical for many applications from drug delivery to bio-analysis, while is of great challenging in sustainability for inescapable wastage of lubricant layer. Herein, an ultrafast lubricant self-mediating (self-replenishing/-absorbing) photothermal slippery surface is designed that achieves sustainable transport of droplet under the irradiation of near infrared light (NIL) even if the lubricant layer is wiped clean completely, as well as at other man-made extreme conditions. The ultrafast lubricant self-mediating performance is caused by synergistic effects of interconnection of porous structure and photothermal expansion of the material. When lubricant on surface is lost, photothermal expansion of material can quickly squeeze the lubricant inside the base to flow into and out of the interconnected porous structure to generate a fresh lubricant layer. Attractively, when the NIL is turned off, the rebuilt lubricant layer can be swiftly self-absorbed into the porous to inhibit unnecessary wastage. Moreover, an arbitrary split of droplet in desired configurations can be achieved by controlling the NIL irradiating route. This sustainable droplet manipulation induced by ultrafast lubricant self-mediating can be extensively applied in microfluidics and micro-reactor settings. 相似文献
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João Borges Luísa C. Rodrigues Rui L. Reis João F. Mano 《Advanced functional materials》2014,24(36):5624-5648
Layer‐by‐Layer (LbL) assembly is a simple and highly versatile method to modify surfaces and fabricate robust and highly‐ordered nanostructured coatings over almost any type of substrate. Such versatility enables the incorporation of a plethora of building blocks, including materials exhibiting switchable properties, in a single device through a multitude of complementary intermolecular interactions. Switchable materials may undergo reversible physicochemical changes in response to a variety of external triggers. Although most of the works in the literature have been focusing on stimuli‐responsive materials that are sensitive to common triggers such as pH, ionic strength, or temperature, much less has been discussed on LbL systems which are sensitive to non‐invasive and easily controlled light stimulus, despite its unique potential. This review provides a deep overview of the recent progresses achieved in the design and fabrication of light‐responsive LbL polymeric multilayer systems, their potential future challenges and opportunities, and possible applications. Many examples are given on light‐responsive polymeric multilayer assemblies built from metal nanoparticles, functional dyes, and metal oxides. Such stimuli‐responsive functional materials, and combinations among them, may lead to novel and highly promising nanostructured smart functional systems well‐suited for a wide range of research fields, including biomedicine and biotechnology. 相似文献
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Spontaneous droplet jumping on micro-/nano-structured superhydrophobic surfaces has been exploited as an efficient means for enhancing steam condensation heat transfer. However, the good performance of such surfaces quickly decays with raising the degree of subcooling, due to the mismatch between the characteristic length scales and droplet sizes when they grow up. Herein, a novel strategy for multiscale droplet regulation is proposed by combining sub-millimeter fin structure with a hierarchical microporous superhydrophobic surface. A superior condensation heat transfer performance is attained on such hierarchical superhydrophobic finned tube (F-SHB), in comparison to the baseline case of superhydrophobic non-finned (SHB) tube under well-controlled test conditions. Although the droplet jumping is not as vigorous as that on the SHB tube, the finned geometry of the F-SHB tube leads to a condensation heat transfer enhancement even under high degrees of subcooling up to 36 K, because of the accelerated departure of large droplets by imposing Laplace force gradient in the presence of V-shaped sub-millimeter fins. This multiscale enhancement strategy is shown to enable a cascading regulation over the entire lifespan of condensate droplets. The fabrication of F-SHB tubes is facile and easy to be scaled up, showing great potential in practical steam condensation applications. 相似文献
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Inkyu Oh Christoph Keplinger Jiaxi Cui Jiehao Chen George M. Whitesides Joanna Aizenberg Yuhang Hu 《Advanced functional materials》2018,28(39)
Traditional dynamic adaptive materials rely on an atomic/molecular mechanism of phase transition to induce macroscopic switch of properties, but only a small number of these materials and a limited responsive repertoire are available. Here, liquid as the adaptive component is utilized to realize responsive functions. Paired with a porous matrix that can be put in motion by an actuated dielectric elastomer film, the uncontrolled global flow of liquid is broken down to well‐defined reconfigurable localized flow within the pores and conforms to the network deformation. A detailed theoretical and experimental study of such a dynamically actuated liquid‐infused poroelastic film is discussed. This system demonstrates its ability to generate tunable surface wettability that can precisely control droplet dynamics from complete pinning, to fast sliding, and even more complex motions such as droplet oscillation, jetting, and mixing. This system also allows for repeated and seamless switch among these different droplet manipulations. These are desired properties in many applications such as reflective display, lab‐on‐a‐chip, optical device, dynamic measurements, energy harvesting, and others. 相似文献
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Karla Perez‐Toralla Abhiteja Konda John J. Bowen Emily E. Jennings Christos Argyropoulos Stephen A. Morin 《Advanced functional materials》2018,28(8)
Synthetic approaches based on the patterned deposition of volatile molecules from the vapor phase are used extensively in the creation of surface‐chemical gradients; however, the ability to generate diffusion‐controlled 1D and 2D gradients from multiple sources remains a challenge. The current work reports a one‐step approach to the synthesis of continuous and periodic chemical gradients with simple and intricate geometries using multiple sources within custom reaction chambers. Specifically, this approach provides precise, simultaneous control over the physicochemical conditions (e.g., concentration, evaporation rate, and direction of diffusion flux of the chemical moieties) and the geometrical parameters (e.g., size, shape, and position) during surface functionalization, thus enabling materials with predictable surface‐chemical gradients applicable to the manipulation and/or organization of liquid droplets and that can generate assemblies of functional solids (e.g., silver nanoparticles) that are transferrable via stamping. These surfaces can be useful to various fields, for example, molecular diagnostics and microfabrication. Furthermore, this work extends the application of these surfaces to the precise placement and manipulation of gas bubbles that can have potential use in, for example, controlling bubble nucleation in processes designed to manage heat transfer. 相似文献
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Surfaces enabling directional liquid transportation are of great interest for a wide range of applications such as water collection, microfluidics, and heat transfer systems. Surfaces capable of lossless, long-range passive transportation of low surface tension (LST) liquids using wettability patterned, liquidlike coatings with minimal contact angle hysteresis are reported. Lossless LST droplet travel distances over 150 mm are achieved, enabled by a two-phase transportation mechanism: morphological transformation from a bulge to a channel shape, followed by directional transportation along the asymmetrical wedge-shaped channel. The developed surfaces can split, merge, and precisely transport various low-surface tension liquids, including alcohols, alkanes, and solvents. The developed transportation strategy can also enhance LST liquid dropwise condensation through continuous removal of the condensate, even on horizontally positioned surfaces without the assistance of gravity. 相似文献
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Designing functional interfaces to control solid/fluid interactions has emerged as an indispensable strategy for developing advanced materials and optimizing current technologies. Surfaces exhibiting special wettability offer many paradigms for regulating fluid behavior in practical applications including oil–water separation and fog harvesting. Nevertheless, the flexible manipulation of air bubbles under water still has room for further exploration. Here, it is reported that the lubricant‐infused slippery (LIS) surface with water repellency is applicable to manipulate bubbles in an aqueous environment. On the basis of the sufficient bubble adhesion, the shaped LIS tracks can be used in guiding the bubble delivery and facilitating continuous bubble distribution. Through the incorporation of an asymmetrical structure into the LIS surface, a triangle‐shaped bubble holder is capable of controlling a single bubble with ease. Moreover, the LIS surface is integrated with a H2 microbubble evolving apparatus, demonstrating a potential method for in situ capture and delivery of microbubbles. The current finding reveals the meaningful interaction between underwater bubbles and the LIS surface, providing several examples for the applications of this bubble carrier, which should shed new light on the development of bubble‐controlling interfaces. 相似文献
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基于表面等离子体激发的光学操控技术由于其所需激光能量低、装置简单,近来引起了广泛关注。采用Kretschmann棱镜耦合法对金膜表面等离子体场进行激发,实现了对直径为10.8μm的聚苯乙烯粒子的有效操控。通过引入一微孔阵列对入射激光光斑图样进行调制,实现了聚苯乙烯微粒在金膜表面的阵列式分布。实验中使用的光源为输出功率20mW的氦氖激光器,所需要的能量密度仅为传统激光光镊能量密度的几十分之一。由于该装置成本低、操控灵活且较低的激光能量密度可以防止对活体细胞的破坏,因此,可在医疗领域中的活体细胞及DNA操控等方面得到应用。 相似文献
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Xueshan Jing Huawei Chen Liwen Zhang Song Zhao Yan Wang Zelinlan Wang Yu Zhou 《Advanced functional materials》2023,33(9):2210883
Droplet manipulation has gradually drawn worldwide attention through diverse potential applications such as microfluidics, and medical diagnostic test. Whereas, the high-precision liquid manipulation on an open surface that is under control at will is still a huge challenge, especially in 3D. Herein, the novel magnetic micropillars array (MMA) is developed for multi-dimensional droplet manipulation, depending on huge symmetric bending deformation under the low magnetic field. In situ observation demonstrated the droplet's behavior and the driving force acted on the droplet is derived from these micropillar's deformation. Two modes, that are, propelling mode and rolling mode are found in horizontal transport that determined by the relative position of crest and droplets and can be transported with excellent accuracy and rapidity. The recombination of the contact liquid between droplets and micropillars occurs in swinging to dynamically adjust the length of the three-phase contact line, which is the main reason for capture-release behavior. Theoretical models of multi-dimensional droplet manipulation are systematically established to demonstrate the underlying mechanism. Finally, several MMA-based operating platforms are built to validate its feasibility in accurate 3D droplet manipulation and exhibit great potential in chemical micro-reactions, bioassays, and the medical field. 相似文献
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Siqi Sun Jiaqi Miao Rong Tan Tieshan Zhang Gen Li Yajing Shen 《Advanced functional materials》2023,33(1):2209769
Structured surfaces have attracted wide attention because of their great potential in directional transport, liquid collection or separation, microfluidics, etc. However, it remains a big challenge to design a surface that can distinguish various liquids, utilize their inherent properties to control their transportation, and realize functional applications. Herein, it is presented an asymmetric soft-structure functional surface (ASFS) with arrayed curvature units that can make the Laplace pressure as a driving force to determine the preferential spreading direction and show abundant transport behaviors for liquids with different surface tensions. With good deformability, the proposed ASFS can directionally transport liquids along complex terrains, e.g., 1D-tilted, 2D-curved, and 3D-helical trajectories. It is also demonstrated that the ASFS can achieve synchronous or asynchronous liquid mixing by choosing appropriate liquids. Moreover, the intelligent response ability allows the ASFS to be a portable contact angle discriminator. This study proposes a new strategy to manipulate liquids via their intrinsic properties and opens new avenues for application-oriented liquid operation surfaces. 相似文献
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Directional transportation and collection of liquids and bubbles are highly desirable in human life and industrial production. As one of the most promising types of functional surfaces, the reported anisotropic slippery liquid‐infused porous surfaces (SLIPSs) demonstrate unique advantages in liquid directional transportation. However, anisotropic SLIPSs readily suffer from the depletion of lubricant when used to manipulate droplets and bubbles, which leads to unstable surface properties. Therefore, fabricating stable anisotropic slippery surfaces for the directional transportation of drops and bubbles remains a challenge. Here, stable anisotropic covalently grafted slippery surfaces are fabricated by grafting polydimethylsiloxane molecular brushes onto directional microgrooved surfaces. The fabricated surfaces show remarkable anisotropic omniphobic sliding behaviors towards droplets with different surface tensions ranging from 72.8 to 37.7 mN m?1 in air and towards bubbles underwater. Impressively, the surface maintains outstanding stability for the transportation of droplets (in air) and air bubbles (underwater) even after 240 d. Furthermore, anisotropic self‐cleaning towards various dust particles in air and directional bubble collection underwater are achieved on this surface. This stable anisotropic slippery surface has great potential for applications in the directional transportation of liquids and bubbles, microfluidic devices, directional drag reduction, directional antifouling, and beyond. 相似文献
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Mariia A. Kuzina Maxi Hoffmann Nikolaj K. Mandsberg Carmen M. Domínguez Christof M. Niemeyer Manfred Wilhelm Pavel A. Levkin 《Advanced functional materials》2024,34(40):2403694
Organogels are polymer networks extended by a liquid organic phase, offering a wide range of properties due to the many combinations of polymer networks, solvents, and shapes achievable through 3D printing. However, current printing methods limit solvent choice and composition, which in turn limits organogels' properties, applications, and potential for innovation. As a solution, a method for solvent-independent printing of 3D organogel structures is presented. In this method, the printing step is decoupled from the choice of solvent, allowing access to the full spectrum of solvent diversity, thereby significantly expanding the range of achievable properties in organogel structures. With no changes to the polymer network, the 3D geometry, or the printing methodology itself, the choice of solvent alone is shown to have an enormous impact on organogel properties. As demonstrated, it can modulate the thermo-mechanical properties of the organogels, both shifting and extending their thermal stability range to span from -30 to over 100 °C. The choice of solvent can also transition the organogels from highly adhesive to extremely slippery. Finally, the method also improves the surface smoothness of prints. Such advances have potential applications in soft robotics, actuators, and sensors, and represent a versatile approach to expanding the functionality of 3D-printed organogels. 相似文献
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Cameron S. Lee Wen Yin Adam P. Holt Joshua R. Sangoro Alexei P. Sokolov Mark D. Dadmun 《Advanced functional materials》2015,25(36):5848-5857
Poly(3‐hexyl thiophene) (P3HT) is widely regarded as the benchmark polymer when studying the physics of conjugated polymers used in organic electronic devices. P3HT can self‐assemble via π–π stacking of its backbone, leading to an assembly and growth of P3HT fibrils into 3D percolating organogels. These structures are capable of bridging the electrodes, providing multiple pathways for charge transport throughout the active layer. Here, a novel set of conditions is identified and discussed for P3HT organogel network formation via spin coating by monitoring the spin‐coating process from various solvents. The development of organogel formation is detected by in situ static light scattering, which measures both the thinning rate by reflectance and structural development in the film via off‐specular scattering during film formation. Optical microscopy and thermal annealing experiments provide ex situ confirmation of organogel fabrication. The role of solution characteristics, including solvent boiling point, P3HT solubility, and initial P3HT solution concentration on organogel formation, is examined to correlate these parameters to the rate of film formation, organogel‐onset concentration, and overall network size. The correlation of film properties to the fabrication parameters is also analyzed within the context of the hole mobility and density‐of‐states measured by impedance spectroscopy. 相似文献
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基于介质上电润湿的液滴产生器的研究 总被引：1，自引：0，他引：1
根据介质上电润湿的基本原理,对用于数字微流控系统的\"三明治\"结构器件中影响液滴输运和产生的因素进行了理论分析,并研制出了一种新型液滴产生器原型:液体被夹在上下两个电极板之间;下极板采用硅作为衬底、LPCVD掺杂多晶硅微电极阵列上热氧化生长的的SiO2薄膜作为介质层;上极板采用ITO透明导电玻璃板作为地电极;另外,在上下极板的表面都均匀旋转涂覆了一层30 nm厚的Teflon薄膜为表面疏水层.实验结果表明,在空气气氛中,该器件在10 Hz 70 V的脉冲电压下成功地实现了从蓄水池中对去离子水滴的分发. 相似文献