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Dynamic oriented wrinkling especially on arbitrary film materials is highly desirable yet remains a great challenge. Here, fabrication of programmable aligned wrinkling patterns on different film/substrate systems via a laser‐direct‐writing (LDW) method is reported, regardless of photofunctionality and transparence of the target films. The key is related to smart introduction of photothermal materials (PTMs) into compliant substrates and even as an independent attachable/detachable layer assembled underneath the film/substrate systems. Experiments and theoretical modeling reveal that with the help of the photothermal effect of PTMs, in situ LDW‐induced localized dynamic anisotropic stress field is responsible for the intriguing LDW path‐parallel aligned wrinkling. Furthermore, dimensional analysis is carried out and explicit solutions quantifying the connection of wrinkling morphology parameters with the LDW conditions are derived for the first time, which enables theoretical pattern designing. It is highlighted that the attachable/detachable assembly strategy for the independent PTMs layer endows arbitrary film/substrate systems with on‐demand photosensitivity when needed, which has been inaccessible previously. As demonstrated, these dynamic oriented wrinkling systems have found broad applications especially in smart soft photonics, e.g., information storage, anticounterfeiting, and responsive optical devices. [ABSTRACT FROM AUTHOR]

Plasmonic nanostructures are frequently utilized to create metasurfaces with a large variety of optical effects. Control over shape and positioning of the nanostructures is key to the function of such plasmonic metasurfaces. Next to lithographic means, directed self‐assembly is a viable route to create plasmonic structures on surfaces with the necessary precision. Here, a combined approach of DNA origami self‐assembly and electron beam lithography is presented for determinate positioning of gold nanospheres on a SiO2 surface. First, DNA origami structures bind to the electron beam‐patterned substrate and subsequently, gold nanoparticles attach to a defined binding site on the DNA origami structure via DNA hybridization. A sol‐gel reaction is then used to grow a silica layer around the DNA, thereby increasing the stability of the self‐assembled metasurface. A mean yield of 74% of single gold nanospheres is achieved located at the determinate positions with a spatial position accuracy of 9 nm. Gold nanosphere dimers and trimers are achieved with a rate of 65% and 60%, respectively. The applicability of this structuring method is demonstrated by the fabrication of metasurfaces whose optical response can be tuned by the polarization of the incoming and the scattered light. [ABSTRACT FROM AUTHOR]

The photodegradation and deadhesion of mussel-inspired polydopamine was reported from nanoscale disassembly to effective mineralization. Various PDA coated templates and PDA hollow structures can be photodegraded by this strategy. The patterned and gradient surfaces were prepared by the "top-down" method under the control of light scope and intensity, respectively. [Display omitted] Mussel-inspired polydopamine (PDA) coating has been utilized extensively as versatile deposition strategies that can functionalize surfaces of virtually all substrates. However, the strong adhesion, stability and intermolecular interaction of PDA make it inefficient in certain applications. Herein, a green and efficient photocatalytic method was reported to remove adhesion and degrade PDA by using TiO 2 -H 2 O 2 as photocatalyst. The photodegradation process of the PDA spheres was first undergone nanoscale disassembly to form soluble PDA oligomers or well-dispersed nanoparticles. Most of the disassembled PDA can be photodegraded and finally mineralized to CO 2 and H 2 O. Various PDA coated templates and PDA hollow structures can be photodegraded by this strategy. Such process provides a practical strategy for constructing the patterned and gradient surfaces by the "top-down" method under the control of light scope and intensity. This sequential degradation strategy is beneficial to achieve the decomposition of highly crosslinked polymers. [ABSTRACT FROM AUTHOR]

Liquid crystal films play a key role in advancing next-generation optical and photonic devices that require a precise in-plane modulation of optical anisotropy. This study employs multiphoton direct laser writing, a high-resolution three-dimensional (3D) printing method, to fabricate pseudoperiodic patterns of lines and grooves on glass surfaces for the in-plane alignment of liquid crystal films. Single layers of lines with submicron thickness and line spacing were fabricated in less than half an hour and forced the in-plane alignment of a liquid crystal film with a thickness of about 10 μm. We validate the method on patterns with singular topologies designed to induce the nucleation of disclination defects with a predetermined spatial arrangement, orientation, and topological strength. Compared to other surface patterning methods, high-resolution 3D printing provides the unique advantage of direct surface fabrication, enabling the creation of nonflat geometries such as terraces and lenses and expanding the design and functionalities of liquid crystal devices. We anticipate that this method will be used to create thin-film devices such as polarization gratings, beam steerers, and q-plates for manipulating polarized and structured light. [ABSTRACT FROM AUTHOR]

When a water drop is impinged upon a superhydrophobic surface with submillimetric surface structures, unconventional impact dynamics such as pancake-like bouncing and asymmetric drop spreading can occur. However, the fabrication of such surface structures often requires an unconventional fabrication approach, which is either time-consuming or costly. In this study, we propose a simple lithography-based approach to manufacture submillimetric cone-shaped pillars over a large area by taking advantage of a unique optical property of hydrogels: a change of refractive index after UV-curing. With an additional hydrophobic nanoparticle coating, we demonstrate that such structures can be used to reduce the contact time during drop impact and induce a drop rotation during rebound. Moreover, the flexibility of hydrogels enables the transfer of surface structures to non-planar substrates. [ABSTRACT FROM AUTHOR]

This study investigates the performance of contact separation and sliding modes of triboelectric Nanogenerators (TENGs) using COMSOL Multiphysics simulation environment. The output performance of a plain surface TENG is compared with square, rectangular, and pyramid‐patterned TENGs. The pyramid pattern emerges as the most efficient geometry, demonstrating a solid output of 95.8 V (Voc) and 0.99 μA (Isc). Advanced 3D printing techniques (3DP) including powder‐based multijet fusion and resin‐based polyjet fusion are utilized to print polyamide 12 (PA12) and VeroClear, respectively. The laser surface patterning technique is used to make precise micropatterns on the surfaces of the VeroClear and PA12 layers, resulting in a consistent and effective surface morphology that enhances the surface area of triboelectric layers, and outperforms traditional approaches of patterning in consistency and efficacy. The validation of simulation results is made where the pyramid pattern is emerged as the most efficient geometry experimentally. Performance is maintained with minimal degradation after 102 cycles, and a 22 μF–63 V capacitor is successfully used to store the generated charge. This study not only sets the path for pre‐experimental analysis using simulation environment but also provides a clear demonstration of advanced manufacturing techniques for printing and patterning 3D‐printed triboelectric materials. [ABSTRACT FROM AUTHOR]

In the present study, we have developed a fully room-temperature and low-toxic surface patterning method for β -Ga _2 O _3 , which consists of the area selective laser-induced crystallization of amorphous Ga _2 O _3 thin films and acid solution etching processes. Highly ( $\bar{2}$ 01)-oriented crystalline β -Ga _2 O _3 thin films with ∼70 nm thickness on α -Al _2 O _3 (0001) substrates were obtained through a combination of room-temperature deposition process and the subsequent excimer laser annealing at a deep ultraviolet wavelength of 248 nm. In conclusion, the area selective crystallized β -Ga _2 O _3 micropatterns were obtained through ultrasonic wet etching with 40% H _3 PO _4 aqueous solution to remove amorphous regions.

The disposal of plastic foam, mostly composed of polystyrene, poses significant environmental challenges due to its high popularity, slow degradation, and low cost. To address this problem, recycling polystyrene foam waste (PF) has emerged as a promising solution to reduce plastic pollution. This paper presents a novel approach to mass‐produce highly ordered, porous honeycomb‐patterned film (hc‐film) using wasted PF as the raw material. The hc‐film is produced using an improved phase separation (IPS) method that utilizes methanol as a suitable pore inducer and template droplet stabilizer. Methanol provides the hc‐film with customizable features such as pore ordering, size, and separation. The freestanding hc‐film, achieved by adopting a water‐soluble polystyrene sulfonate as a scarified layer, can be transferred and utilized as a flexible mold to pattern various solid substrates with complicated surface morphologies using the pre‐impregnated technique. This study demonstrates the potential of this cost‐effective and efficient approach for various applications, such as super/anti‐wetting surfaces, microelectronics, optical devices, sensors, and nanogenerators. [ABSTRACT FROM AUTHOR]

Herein, the fabrication of four different nanostructured silicon surfaces by using a combination of block copolymer micelle lithography is reported on. Nanoparticle hard masks are evaluated for their ability to produce single‐height nanoneedle arrays. Low‐density (3 features μm−2) and high‐density (201 features μm−2) single‐height arrays are produced from Au or α‐Fe2O3 masks, respectively. These single‐height arrays are then used as substrates to produce nanostructured surfaces with two distinct nanoneedle arrays concerning height, diameter, and density. These dual‐height arrays have feature densities of 31 and 9 features μm−2. All surface types are then tested for their antibacterial activity against Gram‐negative bacteria, Pseudomonas fluorescens, over 24 h. No difference in surface coverage of P. fluorescens when comparing the structured silicon surface types to planar controls is observed. However, all of the structured silicon types show an increase in dead cell surface coverage ranging from 9 to 29% compared to planar controls. Density of the pillars appears to be more important than the difference in height of pillars when it comes to antibacterial activity. This work seeks to add to the literature by investigating the effects of feature density, as well as the impact of a dual‐height arrangement of nanoneedles against P. fluorescens. [ABSTRACT FROM AUTHOR]

Patterning diversified properties and surface structure of polymer materials are of great importance toward their potential in biology, optics, and electronics. However, achieving both the patternability of stiffness and microstructure in a reconfigurable manner remains challenging. Here, we prepare amphigels crosslinked by dynamic disulfide bonds, which can be reversibly swollen by immiscible water or liquid paraffin. In the paraffingel form, the materials exhibited a high modulus of 130 MPa due to densified hydrogen bonds. Whereas swollen by water, the modulus fell over two orders of magnitude owing to the destruction of the hydrogen bonds. Via regionalized swelling of the solvents, well‐controlled and rewritable soft/stiff mechanical patterns can be created. On the other hand, the dynamic exchange of the disulfide crosslinking enables mechanophoto patterning to fabricate sophisticated macrogeometries and microstructures. The reconfigurable stiffness‐structure patterning can be manipulated orthogonally, which will create more application opportunities beyond conventional hydrogels and organogels. [ABSTRACT FROM AUTHOR]

Abstract Patterning diversified properties and surface structure of polymer materials are of great importance toward their potential in biology, optics, and electronics. However, achieving both the patternability of stiffness and microstructure in a reconfigurable manner remains challenging. Here, we prepare amphigels crosslinked by dynamic disulfide bonds, which can be reversibly swollen by immiscible water or liquid paraffin. In the paraffingel form, the materials exhibited a high modulus of 130 MPa due to densified hydrogen bonds. Whereas swollen by water, the modulus fell over two orders of magnitude owing to the destruction of the hydrogen bonds. Via regionalized swelling of the solvents, well‐controlled and rewritable soft/stiff mechanical patterns can be created. On the other hand, the dynamic exchange of the disulfide crosslinking enables mechanophoto patterning to fabricate sophisticated macrogeometries and microstructures. The reconfigurable stiffness‐structure patterning can be manipulated orthogonally, which will create more application opportunities beyond conventional hydrogels and organogels.

Materials with contrary wettability have various functions and applications. Common methods such as chemical modification and secondary treatment with solid mask to achieve relevant wettability either have harmful additives or construct fixed shape. Herein, liquid is introduced as a plasma mask for constructing arbitrary area with contrary wettability on hydrophobic textiles. In atmospheric plasma working region, exposed area of textiles achieves hydrophilic while liquid shielding area maintains the original wettability. Water–ethanol mixtures with a broad range of surface tension are chosen as template liquid to meet most hydrophobic textiles with the property of erasable evaporation without residue. Liquid mask with fluidity can be drawn in any shape at any time, meanwhile, plasma treatment highlights the merit of no chemical additive. Higher resolution will be achieved when the operation process is further refined. This study may provide insights for constructing advanced infiltrating materials and replacing solid with liquid in more application scenarios. [ABSTRACT FROM AUTHOR]

The modular synthesis of a series of nanoscale phenylene bicyclophanes with an intraannular orthogonal pillar is described. The compounds are obtained by a Suzuki cross‐coupling condensation and are characterized by mass spectrometry and NMR spectroscopy as well as in situ scanning tunneling microscopy at the solid/liquid interface of highly ordered pyrolytic graphite. In addition, their structures and conformations are supported by quantum chemical calculations, also after adsorption to the substrate. A set of two alkyl chain substitution patterns as well as a combination of both were investigated with respect to their ability to form extended 2D‐crystalline superstructures on graphite. It shows that not the most densely packed surface coverage gives the most stable structure, but the largest number of alkyl chains per molecule determines the structural robustness to alterations at the pillar functionality. [ABSTRACT FROM AUTHOR]

Some sloping peatlands in northern regions often develop surface microtopographic patterns to maintain their water balance and ecosystem functioning. However, we do not know whether and how spatial patterning would influence the water balance and peat formation of permafrost-affected peatlands in relatively dry regions. Here we used data from the field observations and Unmanned Aerial Vehicle (UAV) survey of a slope peatland at an elevation of around 4800 m in the hinterland of the Qinghai-Tibetan Plateau (QTP) to document and understand the topographic controls of water balance and vegetation growth. Our terrain analysis result shows that the peatland—located on the middle section of a hillslope—has a gentle slope of 5.6° ± 2.5°, while the non-peatland upper section has a steep slope of 12° ± 4.5°. The great upstream catchment area and the presence of shallow impermeable permafrost likely create a saturated condition for peat formation. Our UAV results show obvious spatial patterning of abundant pools and ridges across this peatland, and pool sizes and ridge abundance increase with increasing slopes, suggesting that slope-controlled water flow gradient is the main driver of ridge formation and that ridges is to slow down the runoff. UAV-derived greenness values show a positive relationship with the total pool extent locally (R2 = 0.60) and decrease with increasing distance from the individual pools, suggesting sensitive responses of vegetation growth to surface moisture. Thus, enhanced vegetation growth and likely resultant great peat accumulation immediately around pools potentially further differentiate surface microtopography, strengthening the pool stability. We conclude that the local slope gradient, surface patterning (pools and ridges) and permafrost interact together to regulate water flow and maintain water balance, which in turn regulate the vegetation growth, peat accumulation and peatland stability. Our study implies that the delicate water balance maintained partly by microtopography is sensitive to climate change—especially potential extreme hydroclimate events—and natural and human-induced disturbances that may modify the surface patterning and weaken the peatland’s stability, affecting the carbon sequestration ability of this type of peatlands.

We demonstrate the fabrication of good quality surface alignment layers on glass by Direct Laser Writing method using a 2-photon polymerisation technique. We use commercially available photosensitive resins to print alignment layers by scanning the focal point of a femtosecond laser near the resin-glass interface. This results in down to ~ 100 nm thin alignment layers that provide good planar anchoring of 5CB and MLC13300, with the easy axis of alignment along the scanning direction. The azimuthal anchoring strength is ~ 5 × 10−6 J/m2 and is an order of magnitude weaker compared to commercial rubbed polyimide alignment layer. The threshold voltage for Fréedericksz transition in a 90° twisted nematic cell is slightly increased compared to conventional rubbed polyimide for printed alignment layers. The turn-on switching time is longer for printed layers compared to polyimide alignment layers, whereas the turn-off time is shorter for printed alignment layers. The advantage of this new method is in its flexibility, as we demonstrate printing of complex surface alignment patterns with alignment layer thickness below 100 nm. [ABSTRACT FROM AUTHOR]

Efficient roll bonding for the manufacturing of clad strips not only requires surface activation but also is improved by a surface patterning to reduce the initial contact area. This increases contact stresses and facilitates a joining without an increasing rolling force. Experiments to pattern surfaces with deformable inlays during cold rolling for a subsequent bonding in low-oxygen atmosphere were carried out using two types of rolling mills, two types of inlays and two types of assemblies. Digital twins of selected experiments were created by means of the FE simulation software QForm UK 10.2.4. The main set of rolling parameters, which play a significant role during formation of the pattern shape considering deformation of the patterning tool, were investigated. The pilot roll bonding of patterned components under vacuum conditions, provided using vacuum sealer bags, allowed for an experimental realization of this approach. The concept technological chain of roll bonding in a low-oxygen or oxygen-free environment comprises the following stages: roll patterning; surface activation and sealing of the strips in a vacuum bag; subsequent roll bonding of the prepared strips inside the protective bag. The difference between the shape of the pattern created and the initial shape of the mesh insert can be quantitatively described by the change of its angle. This difference reaches maximum values when smaller rolls are used with increased rolling reductions. This maximum value is limited by the springback of the deformed insert; the limit is reached more easily if the inlay is not positioned on the rolling plane. [ABSTRACT FROM AUTHOR]

We introduce a unique soft lithographic operation that exploits stamp roof collapse-induced gaps to selectively remove an alkanethiol self-assembled monolayer (SAM) on Au to generate surface patterns that are orders of magnitude smaller than structures on the original elastomer stamp. The smallest achieved feature dimension is 5 nm using a micrometer-scale structured stamp in a chemical lift-off lithography (CLL) process. Molecular patterns retained in the gaps between stamp features and their circumscribed or inscribed circles follow mathematical predictions, and their sizes can be tuned by altering the stamp structure dimensions, including height, pitch, and shape. These generated surface molecular patterns can function as biorecognition arrays or be transferred to the underneath Au layer for metallic structure creation. By combining CLL process with this gap phenomenon, soft material properties that are previously thought as demerits can be used to achieve sub-10 nm features in a straightforward sketch.

Foulants build-up on the membrane surface followed by polarization is considered to be one of the most critical issues that have limited the application of membranes in different industries because they reduce the permeate flux, increase the required feed pressure, reduce the time intervals between chemical cleanings, and finally, shorten the lifetime of the membranes. Several strategies have been proposed to reduce and control the membrane polarization and fouling mitigation for increasing the permeate flux. The strategies include inserting different spacers and turbulence promoters, pulsation of feed, back-pulsation of permeate, the introduction of air bubbles, patterning of the membrane surface, etc. Among these methods, surface patterning of membranes (MSPs) has been one of the most promising ways to reduce and control polarization at the membrane surface for mitigation of fouling which has recently received much attention. In this regard, in this paper, the state-of-the-art surface patterned membranes for the treatment of different feeds are reviewed. Also, various methods for fabrication and construction of the surface patterned polymeric membranes and the enhancements induced by the surface patterns on the membrane processes' performance are discussed in detail. Finally, the future perspective of this technology is forecast. [Display omitted] • Different techniques for fabrication of surface patterned membranes are reviewed. • The mechanisms and strategies of membrane surface patterning are reviewed. • Performance of the surface patterned membranes in different applications are reviewed. • CFD opportunity for designing the surface patterned membranes is expressed. [ABSTRACT FROM AUTHOR]

Spontaneous surface wrinkling provides a simple universal approach to pattern surfaces for a new generation of smart systems. Dynamic programmable manipulation of surface wrinkling especially with on‐demand wrinkling orientation is highly required yet remains a great challenge. Here, an intriguing azopolymer‐based system with a novel polarization‐responsive dynamic oriented wrinkling behavior is reported. During a linearly polarized light illumination, in situ dynamic aligned wrinkling is induced with the wrinkling orientation perpendicular to the polarization direction, irrespective of as‐imposed boundaries. This polarization‐dependent dynamic wrinkling is attributed to the polarized light‐induced photo‐orientation of azopolymer. This fascinating polarization‐dependent dynamic wrinkling characteristic offers a desirable platform to fabricate unprecedented all‐optically reconfigurable hierarchical wrinkling morphologies with arbitrarily tailorable wrinkling orientation and location. As demonstrated, the polarization‐responsive dynamic wrinkling system has wide applications for photoresponsive soft photonics, in particular as an adoptable nonmechanical beam steering device to differentiate/manipulate light propagation in the case of different incident light polarizations/wavelengths/intensities. [ABSTRACT FROM AUTHOR]

In this work a new nanoscale surface marking technique, namely electron beam damage induced surface marking (EBDISM), is developed and tested for the first time on a fine-grained pure Mg surface. This technique utilizes focused high-energy electron beam of a scanning electron microscope to “burn” dense arrays of nano-scale grid patterns on the sample surface, and it is proved to be very effective for identifying and measuring localised deformation behaviours. However, the surface marking deposited by EBDISM is not permanent and it tends to deteriorate overtime. Cheap, easy to use and versatile, the EBDISM technique has a huge potential for quantitative measurement of strain field and nano-scale deformation analysis.

Abstract The regulation of cell behavior is crucial for understanding many fundamental biological processes and designing novel medical devices. Nano/micropatterning has been developed as a means of controlling cellular properties and behaviors. Using cinnamoyl groups that have undergone photodimerization, we have prepared facile photopatterning films with adjustable surface properties for cell patterning via simple steps. Our strategy for controlling surface properties uses the decrease in free volume induced by photocrosslinking. This paper describes the surface‐patterning properties of photocrosslinkable polymer films and the cell adhesion to their micropatterned surfaces. Upon culturing cells on micropatterned surfaces, preferential cell adhesion, alignment and proliferation are observed in the unexposed regions. Additionally, diverse surface patterns of photocrosslinkable polymer films have been fabricated using various photomasks, enabling effective control of cell adhesion and alignment. The ability to regulate cellular behavior via microfabricated surfaces of photocrosslinkable polymer films enables a new and facile approach for designing scaffolds for the development of novel advanced materials, tissue engineering, and regenerative medicine.

Membrane fouling is a major issue in many membrane applications. There are numerous methods used in attempt to mitigate membrane fouling, with one method being membrane surface patterning. However, it is still unclear how the ratio of foulant size to pattern size affects membrane fouling. In this study, we investigated constant foulant size while varying the pattern size on the membrane surface to be smaller than (300-nm), equal to (10-μm), and larger than (50-μm) the foulant (10-μm) on polyamide nanofiltration membranes. These membranes were compared to a commercial nanofiltration membrane and a control flat synthesized membrane. The membranes were tested with water, 2000 ppm Na 2 SO 4 , and three cycles of a n -dodecane (as oil) brine solution in a dead-end cell to assess the fouling resistance and flux recovery ability of each polyamide membrane type. From the fouling experiments, it was determined that none of the pattern sizes significantly affect the flux recovery ratio, but smaller than and larger than patterns decreased the fouling rate on the polyamide membranes by a small margin. [Display omitted] • Describes a method to synthesize semi-aromatic nanofiltration (NF) polyamide layers on patterned polysulfone supports. • Patterned NF membranes of three sizes were compared to flat NF membranes for oil fouling reduction and flux recovery. • NF membranes with patterns smaller and larger than the 10-μm foulant size showed less flux reduction. • All synthesized NF membranes (flat and patterned) showed similar flux recovery ratios. [ABSTRACT FROM AUTHOR]

Laser-generated surface patterns provide the means for local mechanical interlocking between the joined materials, tunes the wettability of surfaces that come in contact, and generally are the main factor for bonding strength enhancement, especially between dissimilar materials. This paper presents the influence of different patterning overlays generated with a pulsed laser on the surface of stainless-steel sheets. For all experiments, an overlapping degree of 90% has been chosen between three different patterns, while the engraving speed, pulse frequency and number of passes have varied. The textured surfaces’ morphology was assessed through optical microscopy, and the roughness of the surfaces was correlated with the corresponding experimental parameters. The results have indicated promising insights for joining stainless steel to plastic materials, which is otherwise difficult to assess through usual welding techniques.

An appropriate cell microenvironment is key to tissue engineering and regenerative medicine. Revealing the factors that influence the cell microenvironment is a fundamental research topic in the fields of cell biology, biomaterials, tissue engineering, and regenerative medicine. The cell microenvironment consists of not only its surrounding cells and soluble factors, but also its extracellular matrix (ECM) or nearby external biomaterials in tissue engineering and regeneration. This review focuses on six aspects of biomaterial–related cell microenvironments: ① chemical composition of materials, ② material dimensions and architecture, ③ material–controlled cell geometry, ④ effects of material charges on cells, ⑤ matrix stiffness and biomechanical microenvironment, and ⑥ surface modification of materials. The present challenges in tissue engineering are also mentioned, and eight perspectives are predicted.

In this study, solid oxide fuel cell (SOFC) electrolyte layers produced by tape casting method are pressed together with a metal mesh under different isostatic press pressures (10-60 MPa) to form surface patterns on the electrolyte. Effects of isostatic press pressure are investigated via profilometer, performance, impedance and microscopic analyses. Electrochemical measurements show that all cells with patterned electrolyte outperform the reference cell. The analyzes performed reveal that the improvement in cell performance is a result of the locally reduced electrolyte thickness as well as the increased electrolyte-electrode interface areas with surface patterning. The cell with patterned electrolyte pressed at 30 MPa pressure shows the highest peak performance of 0.373 W/cm2. For the reference cell, this value is measured as 0.320 W/cm2. At higher pressing pressures, cracks extending to the electrolyte are detected, especially in the cathode region, depending on the increased pattern depth. These cracks cause performance losses by limiting the improvement in the electrochemical reaction zones, which are expected to increase with the increase in the interfacial areas. [ABSTRACT FROM AUTHOR]

Hydrogels are popular materials for desalination and can significantly reduce the vaporization enthalpy of water; however, there are few reports on hydrogels with a controllable multilevel structural design for water evaporation. Herein, a calcium alginate and traditional Chinese ink-based evaporator (CIE) are proposed and fabricated using directed freezing technology to construct radial channels, followed by freeze-drying and physical cross-linking. Because of the squeezing of ice crystals and the shaping effect of the PDMS template, the prepared evaporator exhibits a sea-urchin-shaped highly geometrical centrosymmetric structure with numerous multilevel pore channels, which promotes the rapid transport of water under different solar incidence angles as the sun rotates as well as overcomes the structural shrinkage of the hydrogel caused by insufficient water supply. Additionally, the radial channels in the spherical hydrogel overcome the traditional limitation of saltwater being continuously concentrated in the same area where the evaporation rate is the highest. As a result, the urchin-structured CIE exhibits a water evaporation rate of 3.52 kg m -2 h -1 at 1 sun irradiation, which is 45.5% higher than that of the unpatterned CIE. This multilevel structural design provides a strategy for the fabrication of an all-day water hydrogel-based evaporator without structural shrinkage under solar irradiation.

Triboelectrification is reported as a surface phenomenon and is explained by the electron cloud overlap model explained in the Wang transition concept. Therefore, the performance enhancement of Triboelectric Nanogenerators (TENGs) need to be explored through strategies to engineer the surfaces for increased surface contact area and surface roughness. Surface patterning strategies holds a significant role in upscaling the performance and widening the fields of application of TENGs. The current review article is dedicated to presenting various surface patterning methods, which comes under the physical modification of surfaces. Techniques such as lithography, plasma assisted methods, laser irradiation techniques, electrochemical anodization and other geometrical patterning are discussed. It is noted that the surface modification offered by laser induced graphene is effective for fabricating high performance TENGs. One of the major advantages reported with lasing polyimide and laser induced graphene composite for TENG application is that the composite could act as an electrode for both dielectric to conductor interface and metal free dielectric-dielectric interfaces. Additionally, block copolymer lithography has been identified to be an effective method for fabricating vertically aligned nanopatterned surfaces with high contact surface area. Apart from that, the pressurised plasma jets in non-thermal plasma treatment are also proved to be highly suitable for effective and selective etching of different types of surfaces. Surface texturing by electrochemical anodization has been employed on metallic substrates for developing high performance TENG electrodes. Current challenges faced by various surface patterning approaches and possible suggestions for future developments are also discussed in detail.

Efficient roll bonding for the manufacturing of clad strips not only requires surface activation but also is improved by a surface patterning to reduce the initial contact area. This increases contact stresses and facilitates a joining without an increasing rolling force. Experiments to pattern surfaces with deformable inlays during cold rolling for a subsequent bonding in low-oxygen atmosphere were carried out using two types of rolling mills, two types of inlays and two types of assemblies. Digital twins of selected experiments were created by means of the FE simulation software QForm UK 10.2.4. The main set of rolling parameters, which play a significant role during formation of the pattern shape considering deformation of the patterning tool, were investigated. The pilot roll bonding of patterned components under vacuum conditions, provided using vacuum sealer bags, allowed for an experimental realization of this approach. The concept technological chain of roll bonding in a low-oxygen or oxygen-free environment comprises the following stages: roll patterning; surface activation and sealing of the strips in a vacuum bag; subsequent roll bonding of the prepared strips inside the protective bag. The difference between the shape of the pattern created and the initial shape of the mesh insert can be quantitatively described by the change of its angle. This difference reaches maximum values when smaller rolls are used with increased rolling reductions. This maximum value is limited by the springback of the deformed insert; the limit is reached more easily if the inlay is not positioned on the rolling plane.

Superrepellent surfaces, such as micro/nanostructured surfaces, are of key importance in both academia and industry for emerging applications in areas such as self-cleaning, drag reduction, and oil repellence. Engineering these surfaces is achieved through the combination of the required surface topography, such as porosity, with low-surface-energy materials. The surface topography is crucial for achieving high liquid repellence and low roll-off angles. In general, the combination of micro- and nanostructures is most promising in achieving high repellence. In this work, we report the enhancement of wetting properties of porous polymers by replication from wrinkled Parylene F (PF)-coated polydimethylsiloxane (PDMS). Fluorinated polymer foam "Fluoropor" serves as the low-surface-energy polymer. The wrinkled molds are achieved via the deposition of a thin PF layer onto the soft PDMS substrates. Through consecutive supercritical drying, superrepellent surfaces with a high surface porosity and a high water contact angle (CA) of >165° are achieved. The replicated surfaces show low roll-off angles (ROA) <10° for water and <21° for ethylene glycol. Moreover, the introduction of the micro-wrinkles to Fluoropor not only enhances its liquid repellence for water and ethylene glycol but also for liquids with low surface tension, such as n-hexadecane. [ABSTRACT FROM AUTHOR]

[Display omitted] In recent years, the combination of factors such as growing population and global climate change has resulted in freshwater shortages. Therefore, water harvesting from the atmospheric fog in order to produce freshwater supply inspired by nature has received much attention. The water harvesting capability of the creatures is significantly based on the combination of both wettability states on their surfaces. In this study, a facile physicochemical hybrid method was used for the fabrication of glass surfaces with contrast wettability. First, fractal and regular repeated geometric patterns were deposited on a glass substrate using brass sheet as donor material by laser induced forward transfer (LIFT) method. Subsequently, stearic acid (SA) treatment was used to convert the wettability of the superhydrophilic (SHL) deposited patterns on glass to superhydrophobic. In order to investigate the effect of the shape of designed patterns on glass surfaces in the water harvesting efficiency, the amount of collected water for a period of time from untreated hydrophilic (HL) glass, superhydrophobic (SHB) glass and hybrid superhydrophobic/hydrophilic (SHB-HL) surfaces were measured. The obtained results indicate that the hybrid of superhydrophobic and hydrophilic regions and selecting the optimal pattern can improve the water harvesting performance by up to 300%. [ABSTRACT FROM AUTHOR]

Polymer stamping is a reliable and cost-effective method for producing charged patterned surfaces. However, charge stability is limited, and they discharge steadily while immersed in polar solvents. Here, we applied polyelectrolytes as the stamping medium to increase this stability. Charged line patterns were fabricated by pressing a polydimethylsiloxane (PDMS) stamp covered with a polyethylenimine (PEI) solution against silicon, glass, or polystyrene. Then, the substrate was immersed in a solution of oppositely charged silver nanoparticles. Finally, silver crystallization on the deposited nanoparticle agglomerates was performed to homogenize the conductive surface. Fabricated structures were characterized by conductive AFM, SEM, and electrical measurements. Simulations of the electric field above the pattern and electrostatic deposition of nanoparticles were performed. The presented method allows for the production of high-resolution microstructures composed of parallel 45 mm paths with a width of 10 μm and a thickness below 100 nm. A conductivity of 104 S/m is high enough to keep a commercial LED on. [ABSTRACT FROM AUTHOR]

In this work a new nanoscale surface marking technique, namely electron beam damage induced surface marking (EBDISM), is developed and tested for the first time on a fine-grained pure Mg surface. This technique utilizes focused high-energy electron beam of a scanning electron microscope to "burn" dense arrays of nano-scale grid patterns on the sample surface, and it is proved to be very effective for identifying and measuring localised deformation behaviours. However, the surface marking deposited by EBDISM is not permanent and it tends to deteriorate overtime. Cheap, easy to use and versatile, the EBDISM technique has a huge potential for quantitative measurement of strain field and nano-scale deformation analysis. [ABSTRACT FROM AUTHOR]

Generating stable and customizable topography on hydrogel surfaces with contact guidance potential is critical as it can direct/influence cell growth. This necessitates the development of new techniques for surface patterning of the hydrogels. We report on the design of a square grid template for surface patterning hydrogels. The template was 3-D printed and has the diameter of a well in a 24-well plate. Hyaluronic acid methacrylate (HA) hydrogel precursor solutions were cast on the 3D printed template's surface, which generated 3D square shape topographies on the HA hydrogel surface upon demolding. The 3D Laser Microscopy has shown the formation of a periodic array of 3D topographies on hydrogel surfaces. 3D Laser and Electron Microscopy Imaging have revealed that this new method has increased the surface area and exposed the underlying pore structure of the HA hydrogels. To demonstrate the method's versatility, we have successfully applied this technique to generate 3D topography on two more acrylate hydrogel formulations, gelatin Methacrylate and polyethylene glycol dimethacrylate. Human neonatal dermal fibroblast cells were used as a model cell line to evaluate the cell guidance potential of patterned HA hydrogel. Confocal fluorescence microscopy imaging has revealed that the 3D surface topographies on HA hydrogels can guide and align the actin filaments of the fibroblasts presumably due to the contact guidance mechanism. The newly developed methodology of 3D topography generation in acrylate hydrogels may influence the cell responses on hydrogel surfaces which can impact biomedical applications such as tissue engineering, wound healing, and disease modeling. • A Simple and Cost-Effective Method to Surface Pattern Hydrogels was developed. • Method versatility was shown by applying the process on 3 different hydrogels. • This method was found to improve the surface area and pore structure of hydrogels. • The fluorescence microscopy imaging has revealed the contact guidance potential. [ABSTRACT FROM AUTHOR]

For developing performing medical devices, the biomechanical adaptation plays a key role for both, the bulk material (at macro scale) and surfaces (at micro/nano scale). As concerning the interaction of living cells with artificial surfaces, the cellular mechano‐sensitivity has direct effects on tissue structure and functions. In this work, surfaces architectures, obtained by self‐nano‐crystallization, were realized on a gum‐alloy as substrate (titanium‐niobium‐zirconium‐iron‐oxygen), using silicone masks with micrometric patterns/perforations, on which a near‐surface‐severe‐plastic‐deformation process was applied. For finding 3D suitable geometries of the perforations and their distribution on the masks, generative design algorithms were developed using dedicated software tools. The masks were obtained by 3D printing using the fused filament fabrication method. Multidirectional repeated mechanical impacts on the sample surface with high velocity balls at high strain rates were applied. Deeper compressive residual stresses are generated, creating a superficial self‐nano‐crystallized structure on un‐covered areas, due to small volume‐multidirectional local plastic deformation. The applied parameters have a direct effect on local micro‐topography and microstructure evolution. [ABSTRACT FROM AUTHOR]

Ultra-short laser (USL)-induced surface structuring combined with nanoparticles synthesis by multiphoton photoreduction represents a novel single-step approach for commercially pure titanium (cp-Ti) surface enhancement. Such a combination leads to the formation of distinct topographical features covered by nanoparticles. The USL processing of cp-Ti in an aqueous solution of silver nitrate (AgNO3) induces the formation of micron-sized spikes surmounted by silver nanoparticles (AgNPs). The proposed approach combines the structuring and oxidation of the Ti surface and the synthesis of AgNPs in a one-step process, without the use of additional chemicals or a complex apparatus. Such a process is easy to implement, versatile and sustainable compared to alternative methodologies capable of obtaining comparable results. Antimicrobial surfaces on medical devices (e.g., surgical tools or implants), for which titanium is widely used, can be realized due to the simultaneous presence of AgNPs and micro/nano-structured surface topography. The processed surfaces were examined by means of a scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM) and Raman spectroscopy. The surface morphology and the oxidation, quality and quantity of AgNPs were analyzed in relation to process parameters (laser scanning speed and AgNO3 concentration), as well as the effect of AgNPs on the Raman signal of Titanium oxide. [ABSTRACT FROM AUTHOR]

Nanoimprint lithography is a highly productive process and has an advantage in its resolution of printed patterns. In this paper, inorganic materials are imprinted using mixtures of nanopowders and polymer binder as starting materials. In our previous work, line-and-space patterns with the smallest pitch of about 8 μ m were shown on sintered ceramic sheets using ceramic powders with the smallest particle size of about 100 nm. In this study, we prepare alumina powders with an average particle size of about 100 nm and five kinds of molds with line-and-space patterns with line widths from 10 μ m to 250 nm. The line-and-space patterns were observed on all sintered samples. Although the patterns were not clear on the finer patterns, this result is remarkable. Also, we discuss how the pattern was affected by mold size and particle size. [ABSTRACT FROM AUTHOR]

Polymeric systems displaying spontaneous formation of surface wrinkling patterns are useful for a wide range of applications, such as diffraction gratings, flexible electronics, smart adhesives, optical devices, and cell culture platforms. Conventional fabrication techniques for wrinkling patterns involves multitude of processing steps and impose significant limitations on fabrication of hierarchical patterns, creating wrinkles on 3D and nonplanar structures, the scalability of the manufacturing process, and the integration of wrinkle fabrication process into a continuous manufacturing process. In this work, 4D printing of surface morphing hydrogels enabling direct fabrication of wrinkling patterns on curved and/or 3D structures with user‐defined and spatially controlled pattern geometry and size is reported. The key to successful printing is to tailor the photopolymerization time and partial crosslinking time of the hydrogel inks. The interplay between crosslinker concentration and postprinting crosslinking time allow for the control over wrinkling morphology and the characteristic size of the patterns. The pattern alignment is controlled by the print strut size—the size of the solid material extruded from the print nozzle in the form of a line. To demonstrate the utility of the approach, tunable optical devices, a solvent/humidity sensor for microchips, and cell culture platforms to control stem cell shape are fabricated. [ABSTRACT FROM AUTHOR]

Abstract Solid surfaces that are immobilized with DNA molecules underlie an array of biotechnological devices. These surfaces may also mediate the self‐assembly of hierarchical DNA nanostructures. However, a number of fundamental questions concerning the structure–function relationship of these biointerfaces remain, including how these DNA probe molecules organize on the surface and how the spatial organization influences molecular recognition kinetics and interfacial affinity of these DNA molecules at the regime where crowding interactions are important (1–10 nm). This mini‐review covers recent advances in understanding this structure–function relationship by spatially resolving surface hybridization events at the single‐molecule level. Counterintuitive cooperative effects in surface hybridization are discussed and as is how modeling these cooperative effects can be used to predict the hybridization kinetics of a prototypical DNA sensor. Future opportunities in using mechanistic understanding to improve the performance and reliability of DNA sensors and form hierarchical supramolecular structures are also discussed.

Surface properties are largely responsible for the biological performance of biomedical devices, suggesting the great necessity of surface modification. Micro-contact printing (μCP) is a versatile surface modification technique that is capable of not only producing defined topographical features but also manipulating surface chemical and biological cues through customized inks. Compared to other surface patterning techniques, μCP offers distinct advantages of low cost combined with high reliability and versatility. This review summarizes the principles and characteristics of μCP and presents the latest advances enabled by μCP in the biomedical field, categorized by its applications in constructing cell culture platforms, biosensing platforms, and devices for other biological applications.