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Reducing energy consumption is one of the most effective ways to solve the problem of energy shortage. In this work, nature-inspired paint microgroove arrays with different periods were fabricated using a one-step laser ablation method. A wind tunnel experiment was performed at two wind speeds, 27.7 and 33.3 m/s, to collect drag force data on smooth and structured paint coatings. The results showed that microgroove arrays oriented perpendicular to the flow direction were beneficial to drag reduction, and a drag reduction rate of up to 7.2% was obtained. Meanwhile, the microgroove arrays induced by laser ablation changed the wettability of the paint surface to hydrophobicity. The contact angle shows a slightly decreasing trend with an increase in the periodic scale. Furthermore, the anticorrosion properties of these microgrooves make them advantageous in harsh environments. The fabricated drag-reducing paint microstructures, with the features of self-cleaning and durability, have the potential to be applied on vehicles to realize speed improvement and energy saving.

Chemically and biologically modified substrates for single-cell patterning have been studied extensively, but physically modified structures for single-cell patterning still need further study. In this paper, physically modified silicon nanostructures were introduced to study their effect on SHSY5Y cells. Double-beam double exposure laser interference lithography combined with metal-assisted etching (MACE) was used to fabricate the physically modified silicon nanostructures. It was found that the cells on the gratings stretched and grew orderly along the grating with a small cell area and almost the same cell length compared with those on the Si wafer (control group). While on the grids, the cells were round with limited spreading, grew independently and had the smallest cell area and cell length. Moreover, the localization ratio of cells adhered onto the areas of nanopillars in the grid structures with different periods has been investigated. The results suggest that the physically modified grid silicon nanostructures can regulate the single-cell localization growth and the rational design of substrate structures can maximize the single-cell localization ratio. The findings provide guidance for the design of physically modified nanostructures and regulating single cell patterning, and a better understanding of single-cell localized growth.

In the past decades, many materials have been studied as carriers for targeted drug delivery. However, there is a need for utilizable and selective carrier materials with few side effects. Here, the magnetic Ganoderma Lucidum Spores (mGLS) as a highly efficient targeted drug delivery carrier were explored. Then the regulatable targeted drug delivery system was verified by loading and releasing of the 5-Fluorouracil (5-FU). The results showed that the maximum of the loaded 5-FU reached 250.23 mg·g−1 in the mGLS. The cumulative release of the 5-FU for the drug delivery system could reach 80.11% and 67.14% in the PBS and HCl after 48 h, respectively. In addition, this system showed the good pharmacokinetic properties in vivo. After 12 h, the blood concentration in the 5-FU@mGLS group kept at 5.3 µg·mL−1 and was four times higher than that in the 5-FU group. In summary, the GLS as a natural microscale core-shell structures appears the striking application in carrier material for oral drug delivery.

Graphene (G) and its derivatives are important nanomaterials with potential medical applications for biosensors and implanting biomaterials. The hydrophobicity and surface microstructures of substrates have great influences on the biological and physical properties of the surface-bound cells. In this work, we used the two-beam laser interference (TBLI) technique to prepare a two-dimensional (2-D) grating structure on the surface of graphene oxide (GO) film. We investigated the effect of GO and the GO film with the 2-D grating structure substrates on the growth behavior of rat brain microvascular endothelial (bEnd.3) cells. The results demonstrated that the cell spreading area and the number of surface-bound cells were closely related to the hydrophobicity of the substrate and the presence of oxygen-containing functional groups (OCGs). Due to the interaction of laser and GO, the GO in the interference area was transformed into reduced graphene oxide (RGO). The grating-structured GO film significantly affected the direction of cell spreading and morphology. It has a good application prospect as a scaffold in tissue engineering, and promising applications in the fields that require highly directional growth of cells, such as nerve injury repair, tendon repair and regeneration.

Various cell culture substrates have been developed for cell patterning to control cell distributions and orientations in tissue engineering, drug screening and regenerative medicine. In this study, a preparation method of modified fiber membranes was applied in the field of cell patterning, and the obtained fiber membranes guided the cell distributions and orientations flexibly. The aligned electrospinning fiber membranes were dip-coated with polydimethylsiloxane (PDMS) to improve the stability of wettability, and then it was treated with oxygen plasma with a photomask to obtain a hydrophilic-hydrophobic surface micropattern. The morphologies, wettabilities and chemical structures of the membranes were analyzed by using a scanning electron microscope (SEM), drop shape analysis instrument, energy dispersive spectrometer (EDS) and Fourier transform infrared (FTIR) spectrometer. The L929 cells were cultured on the obtained membranes to observe the controlled cell distributions and orientations by using a SEM and fluorescence microscope. The results indicate that the treated membranes have the ability to control both cell distributions and orientations simultaneously. This method offers a novel approach to develop cell culture substrates for cell patterning in tissue engineering.

How to effectively utilize the energy of the broad spectrum of sunlight is one of the basic problems in the research of tandem solar cells. Due to their size effect, quantum confinement effect and coupling effect, colloidal quantum dots (QDs) exhibit new physical properties that bulk materials don't possess. CdX (X = Se, S, etc.) and PbX (X = Se, S, etc.) QDs prepared by hot-injection methods have been widely studied in the areas of photovolitaic devices. However, the surfactants surrounding QDs seriously hinder the charge transport of QDs based solar cells. Therefore, how to fabricate high-performance tandem solar cells via ligands engineering has become a major challenge. In this paper, the latest progress of colloidal QDs in the research of all-inorganic tandem solar cells was summarized. Firstly, the improvement of QDs surface ligands and the optimization of ligands engineering were discussed, and the control of the physical properties of QDs films were realized. From the aspects of colloidal QDs, ligand engineering, and solar cell preparation, the future development direction of colloidal QDs solar cells was proposed, providing technical guidances for the preparation of low-cost and high-efficiency nanocrystalline solar cells.

Understanding the cell–substrate interactions has great significance in tissue regeneration therapies. However, the cell–substrate interactions are not well understood because the interface of cell–substrate is typically buried beneath the cells. This research investigated the subsurfaces of fibroblasts cultured on hybrid nanoarrays using atomic force acoustic microscopy (AFAM). We fabricated hybrid silicon nanowires (SiNWs) and silicon nanoholes (SiNHs) on Si substrates to serve as biomimetic nanoarrays by employing laser interference lithography and the metal-assisted chemical etching (MacEtch) method. After the L929 cells were cultured on the nanoarrays, scanning electron microscopy (SEM) and AFAM were employed to investigate the surface and subsurface of L929 cells. It was suggested that fibroblasts could sense the morphology of the hybrid nanoarrays and membrane damage of fibroblasts on the hybrid nanoarrays were related to the nanostructures. This study can help guide the design of biointerfaces and provide a useful tool for the study of cell subsurfaces in diverse biological fields.

A method for creating a diffraction grating (DG) with an in situ variable parameter is proposed. The adaptive DG for operation in visible and IR wavelength consists of the 2D matrix of composites with shape memory effect (SME) with thermally controlled shape. The experimental prototype of the adaptive DG sample was manufactured using the method of local ion etching is shown.

The directional arrangement and extension of cells is of great significance in the tissue engineering field. Great efforts have been made to study the effects of micro- or nano- structures on cell behaviors, but they are still poorly understood. In this work, hybrid micro/nano structures prepared by combining laser marking technology with metal assisted chemical etching (MACE) were introduced to study their effect on the growth behavior of SHSY5Y cells. It was found that the cells on the silicon micro-pit arrays (SiMP arrays, unetched substrate) were arranged orderly along the edge of the micro-pits, stretched and connected with each other, while the cells on the hybrid silicon micro-pit and silicon nano-pillar arrays (hybrid SiMP/SiNP arrays, etched substrates) were also arranged in an orderly manner with a relatively short cell stretch, but displayed a preference for independent growth. In addition, about 90% of cells showed a preference for growing on the area of nano-pillars (NPs), and only 10% of cells on the area of micro-pits (MPs) on the etched substrate. The results showed that the hybrid SiMP/SiNP arrays trapped cells and restricted the cell spreading. Thus, this approach is of great significance for the study of independent growth behavior of cells on the substrate in the field of single neuron research.

Triazene polymer (TP) film was used as the intermediate layer to transfer the Ag micro-stripe in laser interference induced forward transfer (LIIFT). The results showed that the film quality of the intermediate layer would affect the transfer results. The homogeneity of the TP films would affect the completeness and resolution of the transferred Ag micro-stripe. Applied the TP1 film compounded by the solution with higher concentration (20 g/L) of 1,3-diphenyl-1-triazene (DT) and tetrahydrofuran (THF), there was shown scattered Ag nanoparticles (NPs) instead of micro-stripe on the Si receiver. Reducing the solution concentration, with the intermediate layer of TP2 film, the broken micro-stripe was transferred. While the TP3 film was prepared with DT and N, N-Dimethylformamide (DMF) solution and used as the intermediate layer, the unbroken and regular Ag micro-stripe with good resolution was transferred, indicating the TP3 film was more appropriate than TP1 and TP2 films as the intermediate film to transfer the Ag micro-stripe in LIIFT. Combined with the analysis to the film qualities, the effect of the film homogeneity on the transferred results was discussed.

In this study, the method of direct modification of conductive atomic force microscopy (CAFM) probes using focused electron beam induced deposition (FEBID) of platinum (Pt) nanowire is presented. This method allows the restoration of broken tips, as well as regenerates the conduction. The length and diameter of the modified tips were optimized by changing the duration time and electron beam current. The tip diameter before modification was measured to be approximately ∼50 nm, and that after modification was measured to be approximately ∼15 nm, which was significantly decreased. The AFM images of topography and current were collected from the fabricated samples with circular array structures using both commercial and Pt nanowire modified CAFM probes. The resistance of FEBID modified probes was obtained using CAFM voltage spectroscopy in the contact mode on a sputtered Pt surface. The results show that the modified probes exhibit a superior spatial resolution and high stability during AFM scans, which provide a significant advancement for CAFM measurements.

In this paper, silver was used as an antibacterial agent, the periodic micro/nanostructure was fabricated on the surface of titanium alloy by laser-induced interference, and silver was fused with titanium alloy at the same time. It was expected to obtain titanium alloy functional surface with good antibacterial properties and friction reduction. The physical and biological properties of six groups of samples with different silver film thicknesses of 0–500nm, Ag 50nm , Ag 100nm , Ag 200nm , Ag 300nm , Ag 400nm and Ag 500nm were tested. The results showed that the friction coefficient of the modified sample decreases by 60%. All the samples showed good antibacterial activity against S.aureus, which increased with the increase of silver film thickness.

Molybdenum disulfide (MoS 2 ) has been widely used in the field of electrochemical sensing. The characteristics of sensing electrodes affect sensing performance so that it is of great importance to study the surface characteristics of the electrodes. Herein, the surface roughness and wettability of MoS 2 nanosheets-based electrodes were studied by an atomic force microscopy and a contact angle-measuring system respectively. The electrodes modified by MoS 2 nanosheets exhibit significant changes in surface roughness varying from 2.19 nm to 0.22 µm and in the water contact angle varying from $59.9\pm 4.2^{\circ}$ to $72.8\pm 4.0^{\circ}$ . Analysis of surface energy reals that the variation in polar component and dispersion component changes the wettability. In addition, the coating thickness-dependent wettability of the electrodes was further investigated. The measured data suggests that the higher the thickness, the lower the contact angle. The result reveals the interaction between the electrode surface based on MoS 2 nanosheets and water, which paves a new way to improve sensing performance of the electrodes.

Bacteria can cause a variety of diseases, which not only aggravates the economic burden of patients, but also consumes a lot of social medical resources. Therefore, resistance to bacterial infection is a top priority in the treatment of various diseases. In this paper, the flower-like cuprous oxide had been successfully obtained by one-pot hydrothermal method. The shape, morphology, structure and chemical compositions of the as-prepared cuprous oxide were verified by scanning electron microscopy, energy-dispersive X-ray spectrometry X-ray diffraction and X-ray photoelectron spectroscopy. In addition, the antimicrobial effect of flowerlike cuprous oxide had been systematically studied. It was gratifying that the flower-like cuprous oxide showed excellent resistance to Escherichia coli. Thus, the as-prepared Cu 2 O could be regarded as a promising bacteriostatic candidate.

In the manipulation of nanoparticles for precise placement, the relatively low adhesion of the nanoparticles to the substrate surface has emerged as a problem. Owing to the fact that nanoparticles manipulated using atomic force microscopy (AFM) often cannot be accurately placed at their predetermined destinations or may even go astray, becoming “lost,” the success rate of manipulation attempts is low. We investigated the possibility of enhancing the adhesion between magnetic nanoparticles and a substrate surface by modifying a mica substrate with a solution of 3-aminopropyltriethoxysilane (APTES). The morphology of the mica surface before and after modification was analyzed, and the adhesive force was calculated by using AFM in contact mode. The effect of different APTES-solution concentrations on the adhesive force was analyzed as well. The results demonstrate that the adhesion of the nanoparticles to the modified substrate was substantially stronger than their adhesion to an unmodified surface, a finding that can be used to improve the success rate of nanoparticle manipulation.

Conductive atomic force indentation (CAFI) was proposed to study the self‐repair behaviour of the neuronal cell membrane here. CAFI was used to detect the changes of membrane potentials by performing the mechanical indentation on neurons with a conductive atomic force microscope. In the experiment, a special insulation treatment was made on the conductive probe, which turned out to be a conductive nanoelectrode, to implement the CAFI function. The mechanical properties of the neuronal cell membrane surface were tested and the membrane potential changes of neurons cultured in vitro were detected. The self‐repair behaviour of the neuronal cell membrane after being punctured was investigated. The experiment results show that CAFI provides a new way for the study of self‐repair behaviours of neuronal cell membranes and mechanical and electrical properties of living cells.

The laser-interference-induced backward transfer (LIIBT) that occurred during the nanostripe structuring of materials, performed by two-beam laser interference at the ITO glass/silicon wafer system under a normal atmospheric environment. The results showed that the nanostripe structures with nanoparticles (NPs) can be obtained at the laser fluence of 65–95 mJ·cm−2 for the laser duration of 100 and 200 pulses, respectively. The EDX analysis revealed that the silicon element was transferred on the surface of the nanostripe structures. In addition, Raman spectra with the peaks at ~520 cm−1 verified that the crystalline silicon was deposited on the nanostripe structures during the LIIBT process. Furthermore, the photoluminescence (PL) spectrum with the peak at ~395 nm belongs to the In2O3 nanostructure at the laser fluence of 45 mJ·cm−2 for 200 pulses. The peak at ~405 nm corresponds to the silicon nanostructures and it is covered by SiO at the laser fluence of 75 mJ·cm−2 for 200 pulses. The LIIBT shown here would greatly reduce the complexity in the fabrication of the nanostripe structures and give an impetus to the laser-induced backward transfer.

Superhydrophobic surfaces with tunable wettability have attracted much attention in recent years, and many techniques have been developed to fabricate artificial function structures. However, applications of tunable adhesive superhydrophobic surfaces have been limited due to ambiguous structural factors on wettability. In this paper, we studied the relationship between the surface adhesion and geometry parameters of periodic submicron structures, and presented a facile approach for the fabrication of controllable superhydrophobic surfaces with tunable adhesion through laser interference lithography (LIL) combined with inductively coupled plasma (ICP) etching. The wettability properties of periodic geometry structures were selected by tailoring the top area ratio of the pillar array. The findings of this work will contribute to quantifying structural parameters on the submicron scale through the combination of three-beam LIL and ICP etching for designing and developing new systems for micro-droplet manipulation. This approach can find potential applications in many fields such as targeted drug delivery, biomolecular quantitative detection, selective liquid transportation and oil/water separation.

Cancer is currently drawing more and more attention as the leading factor in death worldwide. However, little research has been directed towards investigating the micro/nanoscale mechanical properties of cancer cells treated by targeted drugs to evaluate the model systems of targeted drugs using atomic force microscopy (AFM) nano-indentation, especially in light of the multiple drugs targeting various cancerous cells. This paper aims to compare the mechanical effects of sorafenib tosylate and osimertinib mesylate on hepatoma carcinoma cells and lung cancerous cells using atomic force microscopy from the perspective of a model system based on nano-indentation at the micro/nanoscale, which has rarely been investigated. The Sneddon model is applied to fit the force-distance curves, and the mechanical properties, i.e., Young's moduli, can then be calculated. For the SMMC-7721 cells, osimertinib mesylate is a more effective inhibitor than sorafenib tosylate. For the A549 cells, osimertinib mesylate and sorafenib tosylate both have an obvious inhibitory effect. The experimental results may make possible contributions to the diagnosis and treatment of early-stage cancers.

In this study, the bi-layered disulfiram-loaded fiber membranes with the antibacterial activity and different surface wettabilities are prepared using electrospinning technology. In the application of wound dressing, the hydrophilic surface of fiber membranes is beneficial for cell adhesion and drug release to heal the wound. Meanwhile, the outside hydrophobic surface is able to block water penetration to reduce the probability of wound infection. The obtained bi-layered drug-loaded fiber membranes are composed of polyvinylidene fluoride (PVDF) bottom surface and disulfiram (DSF)/polylactic acid (PLA) top surface. To modify the top surface wettability, the oxygen plasma modification of bi-layered membranes was carried out. The morphology, wettability, and chemical compositions of bi-layered drug-loaded fiber membranes were analyzed using the scanning electronic microscope (SEM), drop shape analysis instrument, X-ray diffractometer (XRD), and X-ray photoelectron spectrometer (XPS). The bi-layered disulfiram-loaded membranes showed the potent antibacterial activity in vitro against both Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). It was found that the bi-layered membranes had good biocompatibility with L929 cells. Thus, the obtained bi-layered disulfiram-loaded fiber membranes are suitable for wound dressing application.

The nanoprobe is a powerful tool in scanning probe microscopy (SPM) that is used to explore various fields of nanoscience. However, the tips can wear out very fast due to the low stability of conventional probes, especially after the measurement of high currents or lateral friction, which results in image distortion and test imprecision. Herein, a novel functional nanoprobe is presented using graphene sheets in a high-quality graphene solution wrapped round a plasma-treated conventional Pt-Ir coated nanoprobe, which shows highly stability and resistance to degradation, leading to a significantly increased lifetime. Furthermore, we show that the graphene-wrapped nanoprobes have the advantages of enhanced electrical conductivity and reduced tip–sample friction, compared with Pt-Ir coated nanoprobes. The simplicity and low cost of this method make it valuable to various functional graphene-wrapped nanoprobes and applications.

Despite the success of previous methods for fabricating underwater superoleophobic surfaces, most of the surfaces based on soft materials are prone to collapse and deformation due to their mechanically fragile nature, and they fail to perform their designed functions after the surface materials are damaged in water. In this work, the nanosecond laser-induced oxide coatings on hydrophilic bulk metals are reported which overcomes the limitation and shows the robust underwater superoleophobicity to a mechanical challenge encountered by surfaces deployed in water environment. The results show that the surface materials have the advantage that the underwater superoleophobicity is still preserved after the surfaces are scratched by knife or sandpaper and even completely destroyed because of the hydrophilic property of damaged materials in water. It is important that the results provide a guide for the design of durable underwater superoleophobic surfaces, and the development of superoleophobic materials in many potential applications such as the oil-repellent and the oil/water separation. Additionally, the nanosecond laser technology is simple, cost-effective and suitable for the large-area and mass fabrication of mechanically durable underwater superoleophobic metal materials.

The micro-stripe structure was prepared by laser interference induced forward transfer technique, composed of Ag nano-particles (NPs). The effects of the film thickness with the carbon nano-particles mixed polyimide (CNPs@PI), Ag film thickness, and laser fluence were studied on the transferred micro-stripe structure. The periodic Ag micro-stripe with good resolution was obtained in a wide range of CNPs@PI film thickness from ∼0.5 to ∼1.0 μm for the Ag thin film ∼20 nm. The distribution of the Ag NPs composing the micro-stripe was compact. Nevertheless, the average size of the transferred Ag NPs was increased from ∼41 to ∼197 nm with the change of the Ag donor film from ∼10 to ∼40 nm. With the increase of the laser fluence from 102 to 306 mJ·cm−2 per-beam, the transferred Ag NPs became aggregative, improving the resolution of the corresponding micro-stripe. Finally, the transferred Ag micro-stripe exhibited the significant surface enhanced Raman scattering (SERS) property for rhodamine B (RhB). While the concentration of the RhB reached 10–10 mol·L−1, the Raman characteristic peaks of the RhB were still observed clearly at 622, 1359 and 1649 cm−1. These results indicate that the transferred Ag micro-stripe has potential application as a SERS chip in drug and food detection.

Herein, we explored an effective way to obtain uniform copper nanoparticles by irradiating Cu2O microparticles in ethanol with a 1064 nm laser. The morphology, structure and chemical composition of as-prepared copper nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. It is interesting that the diameter of obtained spherical copper nanoparticles can be finely tuned by changing the irradiation time. Moreover, we also found that the particle size of copper nanoparticles can be reduced to ~63 nm when the irradiation time is 30 min. Inspired by the fast-developing non-enzymatic glucose sensors, the electrochemical activity of the copper nanoparticles toward glucose in alkaline media was further investigated. Notably, the electrochemical results reveal that the prepared copper nanoparticles possess a good prospect in non-enzymatic glucose sensor.

Two-dimensional (2D) molybdenum sulfide has been considered a promising electrode material for high-performance supercapacitor owing to its superior electrochemical properties. However, molybdenum sulfide suffers from severe layers stacking and agglomeration, which lower the number of electrochemically active sites along the basal plane and result in dramatic and fast fading of capacity upon cycling and low Coulombic efficiencies. Herein, we fabricated the hierarchical Co3S4/CoS/MoS2 nanoflakes array grow on carbon cloth via a new scalable technique using the leaf-like Co-ZIF-L as a precursor. An optimal structure and electrochemical performance of the hierarchical nanomaterial are achieved after tune the stoichiometric ratio of the reactors. Due to the unique morphology, plenty of macropores, and vast of active sites, the hierarchical bimetallic sulfides nanoflakes array as an electrode not only present high specific capacitances (805.7 F g−1 at 1 A g−1) but also long cycle lifespan (91.2% of the initial value after 6000 cycles) and 100% of Coulombic efficiency. The strategy developed here can be further extended to design and construct other advanced heterostructure metal sulfides electrode materials for highly efficient energy storage and conversion applications, such as electrocatalysts, metal-ions batteries, and fuel cells.

In this paper, large-area magnetic-plasmonic Ni@Au core–shell nanoparticle arrays (NPAs) with tunable compositions were successfully fabricated by direct laser interference ablation (DLIA) incorporated with thermal dewetting method. The magnetic properties of the Ni@Au core–shell NPAs were analyzed and the saturation magnetization (Ms) of the Ni80@Au20 nanoparticles was found higher than that of nickel-only nanoparticles with the same diameter. The surface enhanced Raman scattering (SERS) property of the Ni@Au core–shell NPAs was then examined using the Rhodamine 6G (R6G) as a Raman reporter molecule and a SERS enhancement factor of 2.5×106 was achieved on the Ni50@Au50 NPA substrate, which was of 9 times higher than that for Au nanoparticles with the same size distribution. It was due to the enhanced local surface plasmon resonance (LSPR) between the ferromagnetic Ni cores and the surface polariton of Au shells of each nanoparticle. The fabrication of the Ni@Au core–shell NPAs with different compositions offers a new avenue to tailor the optical and magnetic properties of the nanostructured films for chemical and diagnostic applications.

Multifunctional antireflective coatings have practical applications as important optical components in many fields, particularly for optical devices and imaging systems. However, a good antireflection application in the visible region is often unsatisfactory for mid-infrared devices, and the difficulty in obtaining multiple capabilities simultaneously is one of the main factors limiting their applications. In this work, hierarchical moth-eye structures with superhydrophobicity were fabricated via inductively coupled plasma reactive ion etching (ICP-RIE) using nanodisk-array masks, which were formed by three-beam laser interference lithography (LIL), for improving the ultra-broadband optical properties. The uniform antireflection efficiency, which was close to 1% reflectivity covering over the visible and mid-infrared wavelength range, was exhibited by the moth-eye structures with high-quality pillar arrays. Additionally, irregular nanostructures were tailored onto the top of the pillars to generate hierarchical moth-eye structures for simultaneously obtaining both the superhydrophobic and anticorrosive properties. The fabricated antireflective structures, with the features of self-cleaning and durability, have the advantage of being for long-term use in harsh environments.

Nanostructures and nanoparticles are two typical structures which have already been widely employed as the Surface Enhanced Raman Scattering (SERS) substrates. In most studies, they are employed separately as SERS substrates. Recently, the hierarchical structures including nanostructures and nanoparticles present better SERS characteristics. However, how to machine such hierarchical structures is a big problem. In the present study, a novel method integrating the nanoindentation process and chemical redox reaction to machine the hierarchical SERS substrate is provided. Micro/nanostructures are formed on the Cu(110) plane first, and then Ag nanoparticles are generated on the structured Copper surface. Effects of parameters of the indentation process and the corrosion times in the AgNO3 solutions on the Raman intensities of the SERS substrate with hierarchical structures are experimentally studied. The intensity and distribution of the electric field of single and multi Ag nanoparticles on the surface of plane and micro/nanostructures are studied with the COMSOL software. The feasibility of the hierarchical SERS substrate is verified using R6G molecules. Finally, the enhancement factor of malachite green molecules can reach to 5.089×109, which proves that the method is simple, replicable and low cost method for machining the hierarchical SERS substrate.

In this paper, a method is presented to detect the different phases of epoxy cross-linking process and the subsurface structures of SU-8 thin films by atomic force acoustic microscopy (AFAM). The AFAM imaging of SU-8 thin films was investigated under different exposure and bake conditions. Optimized conditions were obtained for the cross-linking of SU-8 thin film at the exposure does of eight laser pulses with the laser fluence 10 mJ cm-2 per pulse and the post exposure bake (PEB) time at 90 s. The subsurface structures of undeveloped SU-8 thin films were visible in the AFAM images. This method provides an effective and low-cost way for the determination of different phases of epoxy cross-linking process in nanostructured compounds, for the non-destructive testing of subsurface defects, and for the evaluation of the quality of patterned structures.

In this research, a novel method is proposed to improve DNA straightening under an applied electric field to facilitate imaging in a liquid phase by modifying the substrate with varying Mg

Laser induced forward transfer technology has been reported to print various patterns of 2D and 3D structures in microfabrication for its fascinating characteristics such as non-contact and simple fabrication process. However, the efficiency and throughput are the drawback especially for manufacture of periodical polymer micro-stripes. Here, we proposed a laser interference induced forward transfer (LIIFT) technique, which could produce periodical polymer micro-stripes with high efficiency. The experiment results showed that the good micro-stripe of the polyimide (PI) had been transferred from the PI film, in which the thickness of the PI film, the laser fluence and the pulse number were ~1.2 µm, 39 mJ·cm−2 and 50, respectively. In addition, the relationship of the micro-stripes was systematically analyzed with the laser fluence, the pulse number and the thickness of donor film, respectively. Furthermore, the Fourier transform infrared(FT-IR)spectra showed that these characteristic valleys of the micro-stripe were coincident with those of the PI film, indicating that the micro-stripes transferred were not changed for their composition during the laser processing. Finally, the transferring process was discussed to analyze the formation of the transferred micro-stripes.

Herein, we report for the first time the use of ethanol for the switchable underwater wettability on a rough titanium dioxide (TiO2) surface. The rough TiO2 thin films on the titanium surfaces are fabricated by the high speed wire electrical discharge machining (HS-WEDM) processes, and the resultant surfaces show the switch between underwater superhydrophobicity and oleophobicity via ethanol immersion and dark storage. The underlying mechanism of the switch is depicted, and the result shows that during the ethanol immersion and dark storage, the change of hydroxyl groups leads to the switch. Considering that the use of ethanol is time-saving and low-cost, we anticipate that the use of ethanol will open up a new way of surface wettability change.

The electrochemical oscillations that occur during the etching of InP and the three-dimensional (3D) porous structure of the resulting material were studied by performing electrochemical etching in a 3.5 mol L−1 NaCl solution at different temperatures and current densities. The characteristics of the oscillations were modified by adjusting the electrochemical parameters. The relationship between the oscillations and the porous structure of the etched InP was investigated. In the experiments, porous InP with a gradient-index (GI) structure was formed at relatively low temperatures (10–22 °C) and current densities (100–300 mA cm−2). Furthermore, two types of incomplete pores observed in the bottom layer of the porous structure of InP were found to correspond to incomplete oscillations (one-quarter and one-half of an oscillation, respectively), which provided useful insight into how pore growth proceeds in the etched InP. Based on the results obtained in this work, the growth mechanism of porous InP is discussed in this article.

In this work, a method for the fabrication of two- and three-dimensional curved surfaces with robust underwater superoleophobicity is reported for the first time on light alloys (including 5083 Al and TC4 Ti alloys) through the high speed wire electrical discharge machining (HS-WEDM). The surface morphology and compositions were characterized by scanning electron microscope and energy-dispersive X-ray spectrometer. The results showed that rough structures and a layer of oxidization were created on the light alloys by HS-WEDM cutting. The two- and three-dimensional structured curved surfaces after an ethanol immersion exhibited the extreme underwater superoleophobic property with the high oil contact angle and low oil sliding angle. More importantly, the underwater superoleophobic surfaces with the three-dimensional curved features could have many new applications. In order to use the potential functions, the durability of the fabricated samples was tested and the results showed that the samples still exhibited the underwater superoleophobic property after the underwater storage and physical mechanism tests. Additionally, this method is versatile, simple, environment-friendly, and cost-effective.

Nature gives us a large number of inspirations in designing functional materials. Many plant leaves with self-cleaning properties are ubiquitous in nature. These plants have hierarchical structures, which have extreme repellency to liquids and have considerable technical potential in various applications. Herein, we present a method for fabricating bionic taro leaf surfaces by direct laser interference lithography (DLIL) and hydrothermal treatment. The micro-pillar array structure (MPA) was fabricated by DLIL, and a layer of nano-grass structure (NG) was grown on it by hydrothermal treatment. Experiments indicate that the hierarchical composite structures not only have a satisfactory superhydrophobic function with the apparent contact angle (CA) of 172° and sliding angle (SA) of 4°, but also have a strong anti-icing ability with the delay time (DT) of 3723 s. The method is simple and high-efficient for fabricating bionic self-cleaning and anti-icing surfaces.

The effects of AC/DC electric fields on stretching DNA molecules were discussed in this work. In the experiments of stretching DNA molecules with AC/DC electric fields, the voltage range was changed from 0[Formula: see text]V to 10[Formula: see text]V, and the frequency of AC electric field was kept at 50[Formula: see text]kHz. An atomic force microscope (AFM) was used to obtain DNA distributions under different electric fields. DNA molecules were curved and randomly distributed in solution if there was not any force applied to them. When an AC electric field was applied to the DNA sample, the curvature of DNA molecules was decreased gradually, and the stretching result was more obvious with the increase of voltage from 0.1[Formula: see text]V to 5[Formula: see text]V. The DNA molecules were broken when the voltage was increased to 6[Formula: see text]V. However, under the DC electric field, the stretching result of DNA molecules reached to their optimum state when the voltage was 2[Formula: see text]V, and they kept their steady state even though larger electric field intensities applied to the electrodes. The results can be used for the study of DNA–DNA, protein–DNA and quantum dot–DNA interactions and for the exploration of DNA biophysical properties.

In this paper, we introduce a method for the assembly of micropatterned bimetallic nanoparticles (NPs) with controllable patterns and particle sizes on laser interference-structured substrates. The microstructures of interference patterning in conjunction with the nanostructures fabricated by the direct laser interference ablation (DLIA) were used as the templates for the assembly of patterned NPs in thermal dewetting processes. The location and particle size of micropatterned Au-Ni NPs formed were well-controlled by the nanostructures on the substrate surface. The magnetic domain pattern of as-annealed Au-Ni NPs is consistent with the topography of the silicon templates. The DLIA method provides a one-step new way for the large-area and high throughput fabrication of patterned NPs with the templated dewetting method. It can be easily extended to many metal combinations and has wide applications such as magnetic recording, plasmon-enhancement and other functional nanostructured elements and devices.

We present a method for fabricating ordered arrays of metal nanoparticles over a large area. In this method, a simple two-step process combining laser interference patterning (LIP) and thermal dewetting was developed. Two-dimensional (2D) arrays of Ni nanoparticles with uniform sizes and narrow interparticle distances were fabricated on laser-interference patterned silicon substrates. The mechanism for the self-organization due to the modified Rayleigh instability was analyzed.

A simple technique of two-step growth was employed to fabricate homogeneous ZnO core/shell nanorod arrays which were composed of ZnO nanodisk shell layer on the surface of ZnO nanorod arrays. The ultraviolet (UV) response characteristics of the device were measured. The homogeneous ZnO core/shell photodetector had remarkably enhanced response and recovery speed compared with pure ZnO nanorod arrays. It indicated that surface homogeneous coating can be an alternative method to enhance the response and recovery properties of the ZnO nanorod array photodetectors.

Biomechanical properties of cells are altered by many diseases. Cancer cell metastasis is related to the properties such as the cell stiffness that influences cell proliferation, differentiation and migration. In this paper, we used an atomic force microscope to analyze the colchicine-induced effects on the mechanical properties of hepatocyte (HL-7702 cells) and hepatoma cells (SMCC-7721 cells) in culture at the nanoscale. The cells were exposed to a solution with a normal dose of colchicine for two, four and six hours. Surface topographic images showed that colchicine decreased the stability of the cytoskeleton. After the same six-hour treatment in a solution with a normal dose of colchicine, the biomechanical properties of HL-7702 cells were almost unchanged. However, the stiffness and the adhesion force of the SMCC-7721 cells were clearly increased (more than twofold of the normal values), especially after four hours. The deformability of SMCC-7721 cancer cells was significantly decreased within the six-hour treatment in the solution with a normal dose of colchicine. Analysis of the biomechanical properties of post-treatment hepatoma cells provided a complementary explanation for the mechanism of action of colchicine on cells at the nanoscale. This method is expected to allow the monitoring of potential metastatic cancer cell changes, thus preventing the emergence and the transmission of disease, and improving the diagnosis of cancer.