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.

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 TiO2-H2O2 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 CO2 and H2O. 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.

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.

The undesirable dendrite growth induced by non-planar zinc (Zn) deposition and low Coulombic efficiency resulting from severe side reactions have been long-standing challenges for metallic Zn anodes and substantially impede the practical application of rechargeable aqueous Zn metal batteries (ZMBs). Herein, we present a strategy for achieving a high-rate and long-cycle-life Zn metal anode by patterning Zn foil surfaces and endowing a Zn-Indium (Zn-In) interface in the microchannels. The accumulation of electrons in the microchannel and the zincophilicity of the Zn-In interface promote preferential heteroepitaxial Zn deposition in the microchannel region and enhance the tolerance of the electrode at high current densities. Meanwhile, electron aggregation accelerates the dissolution of non-(002) plane Zn atoms on the array surface, thereby directing the subsequent homoepitaxial Zn deposition on the array surface. Consequently, the planar dendrite-free Zn deposition and long-term cycling stability are achieved (5,050 h at 10.0 mA cm-2 and 27,000 cycles at 20.0 mA cm-2). Furthermore, a Zn/I2 full cell assembled by pairing with such an anode can maintain good stability for 3,500 cycles at 5.0 C, demonstrating the application potential of the as-prepared ZnIn anode for high-performance aqueous ZMBs.

Parallel lithographic deposition of polymers onto counterpart substrates is a widely applied surface manufacturing operation. However, polymers may only be soluble in organic solvents or are insoluble at all. Solvent evaporation during stamping may trigger hardly controllable capillarity-driven flow processes or phase separation, and polymer solutions may spread on the counterpart substrates. Solvent-free stamping of melts prevents these drawbacks. Here, a stamp design for the deposition of melts is devised, which intrinsically circumvents ink depletion. The stamps\' topographically patterned contact surfaces with protruding contact elements contacting the counterpart substrates consist of a nanoporous gold layer with a thickness of a few micrometers. The nanoporous gold layer is attached to a molten polymer layer, which is support for the nanoporous gold layer and ink reservoir at the same time. The nanoporous gold layer in turn stabilizes the topography of the stamps\' contact surfaces. As examples, arrays of submicron microdots of polystyrene and poly(vinylidenefluoride-trifluoroethylene) (PVDF-TrFE) are manufactured. The P(VDF-TrFE) microdots are partially crystalline, ferroelectric, and can be locally poled. It is envisioned that the methodology reported here can be automatized and may be extended to functional low-molecular-mass compounds, such as active pharmaceutical ingredients.

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.

UNASSIGNED: We aimed to elucidate the effects of the micro-structure of the pyrolytic carbon for artificial heart valves on its hydrodynamic performance.
UNASSIGNED: Bileaflet mechanical valves of GKS 23 and 29 A were randomly selected. According to ISO5840, mean transvalvular pressure (MPG), regurgitation fraction (RF), and effective orifice area (EOA) of valve were assessed. Then, parallel-groove pattern was constructed by laser etching on leaflet surface, and the valves were subjected again to the same test.
UNASSIGNED: Compared with before patterning at 2, 3.5, 5, and 7 L/min, the MPG of the valves in two specifications were higher, the EOA was larger in 23 A, but smaller in 29 A, and the RF was contrary to EOA. At 5 L/min, the RF in both specifications was lower after etching at 45 bpm. At 70 bpm however, the RF in 23 A decreased, in 29 A increased.
UNASSIGNED: The parallel-groove pattern on leaflet surface affected the hemodynamic performance of the valve prostheses.

Surface patterning is a promising strategy to overcome the trade-off effect of separation membranes. Herein, a bottom-up patterning strategy of locking micron-sized carbon nanotube cages (CNCs) onto a nanofibrous substrate is developed. The strongly enhanced capillary force triggered by the abundant narrow channels in CNCs endows the precisely patterned substrate with excellent wettability and antigravity water transport. Both are crucial for the preloading of cucurbit[n]uril (CB6)-embeded amine solution to form an ultrathin (∼20 nm) polyamide selective layer clinging to CNCs-patterned substrate. The CNCs-patterning and CB6 modification result in a 40.2% increased transmission area, a reduced thickness, and a lowered cross-linking degree of selective layer, leading to a high water permeability of 124.9 L·m-2 h-1 bar-1 and a rejection of 99.9% for Janus Green B (511.07 Da), an order of magnitude higher than that of commercial membranes. The new patterning strategy provides technical and theoretical guidance for designing next-generation dye/salt separation membranes.

We report a straightforward method for creating large-area, microscale resolution patterns of functional amines on self-assembled monolayers by the photoinduced local acidification of a flat elastomeric stamp enriched with photoacid. The limited diffusivity of the photoactivated merocyanine acid in poly(dimethylsiloxane) (PDMS) enabled to confine efficient deprotection of N-tert-butyloxycarbonyl amino group (N-Boc) to line widths below 10 μm. The experimental setup is very simple and is built around the conventional HD-DVD optical pickup. The method allows cost-efficient, maskless, large-area chemical patterning while avoiding potentially cytotoxic photochemical reaction products. The activation of the embedded photoacid occurs within the stamp upon illumination with the laser beam and the process is fully reversible. Preliminary positive results highlight the possibility of repeatable use of the same stamp for the creation of different patterns.

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.