Bin-Bin Xu

Flexible Nanowiring of Metal on Nonplanar Substrates by Femtosecond‐Laser‐Induced Electroless Plating

However,thelithographicrouteshowsstrongdemandsonthesurfaceflatnessofeachlayerin the multilevel chip architectures. To meet the processingnature of lithography, a global planarization of interlayermetals by chemical–mechanical polishing is therefore neededto reduce the interval between the metal layer and thephotomask, and to guarantee exposure resolution when wiresreachthesub-300nmscale.Two-photonabsorption(TPA)hasalso been tried for the fabrication of metal microstructures byusing suitable salt solutions as the metal source and photo-sensitive molecules as the photoinitiator.

Remote manipulation of micronanomachines containing magnetic nanoparticles

We report remote manipulation of micronanomachines containing magnetic nanoparticles. Surface-modified Fe(3)O(4) nanocrystals were synthesized as doping agents of the photopolymerizable resin, which was pinpoint written by femtosecond laser-induced two-photon photopolymerization to create microsprings. Owing to the nature of superparamagnetism of Fe(3)O(4) nanoparticles, force exerted to the microsprings relies sensitively on the field gradient of the external ferromagnet, and various motions like elongation, bending, and swing are achieved in a well-controllable remote manner. As a noncontact, sensitive, easy, and environmentally friendly approach, the magnetic driving of micronanomachines may play an important role for nano and biological applications.

A facile approach for artificial biomimetic surfaces with both superhydrophobicity and iridescence

Biomimetic surfaces are attracting more and more research attention because of the amazing characteristics of living biological species, such as iridescence in flowers of hibiscus trionum and tulipa, and superhydrophobicity on the lotus leaf. Despite numerous efforts for producing the fascinating micro-nanostructures that present either iridescence or superhydrophobicity, there is almost no reports on artificial surfaces that posses both simultaneously apart from a few examples on self-organized colloidal particles. Here, we report bio-inspired charming photonic surface structures consisting of regular micro-needle arrays covered with nano-metal protrusions, which are prepared by multibeam interference patterning plus electroless plating. The multibeam laser approach features rapidness, simplicity and ease of large-area fabrication, for example fabrication of a uniform area of 600 mm2 took less than 1 min. The attained hierarchical artificial surface layers exhibit not only superhydrophobic ability, but also brilliant iridescence, which may be useful as a novel type of decoration layer for buildings, cars, and even clothes.

Solvothermal synthesis of nanoporous polymer chalk for painting superhydrophobic surfaces.

Reported here is a facile synthesis of nanoporous polymer chalk for painting superhydrophobic surfaces. Taking this nanoporous polymer as a media, superhydrophobicity is rapidly imparted onto three typical kinds of substrates, including paper, transparent polydimethylsiloxane (PDMS), and finger skin. Quantitative characterization showed that the adhesion between the water droplet and polymer-coated substrates decreased significantly compared to that on the original surface, further indicating the effective wetting mode transformation. The nanoporous polymer coating would open a new door for facile, rapid, safe, and larger scale fabrication of superhydrophobic surfaces on general substrates.

A SERS-active microfluidic device with tunable surface plasmon resonances†

A surface‐enhanced Raman scattering (SERS)‐active microfluidic device with tunable surface plasmon resonances is presented here. It is constructed by silver grating substrates prepared by two‐beam laser interference of photoresists and subsequent metal evaporation coating, as well as PDMS microchannel derived from soft lithography. By varying the period of gratings from 200 to 550 nm, surface plasmon resonances (SPRs) from the metal gratings could be tuned in a certain range. When the SPRs match with the Raman excitation line, the highest enhancement factor of 2×107 is achieved in the SERS detection. The SERS‐active microchannel with tunable SPRs exhibits both high enhancement factor and reproducibility of SERS signals, and thus holds great promise for applications of on‐chip SERS detection.

Maskless laser tailoring of conical pillar arrays for antireflective biomimetic surfaces

Herein, we report a facile approach for rapid and maskless production of subwavelength structured antireflective surfaces with high and broadband transmittance-direct laser interference ablation. The interfered laser beams were introduced into the surface of a bare optical substrate, where structured surfaces consisting of a micropillar array were produced by two-step laser irradiation in the time frame of seconds. A multiple exposure of the two-beam interference approach was proposed instead of multiple-beam interference to simply realize planar patterns of a high aspect ratio. Tall sinusoidal pillars were created and shaped by pulse shot number control. As an example of the application, zinc sulfide substrates were processed with the technology, from which high transmission at an infrared wavelength, over 92%, at normal incidence was experimentally achieved.

On-Chip Catalytic Microreactors for Modern Catalysis Research

Over the past two decades, microfluidics, represented by lab‐on‐a‐chip (LoC) systems, have been developed because of their unique advantages of low reactant consumption, environmental friendliness, high safety, high efficiency, high sensitivity, portability, and easy handling of reactants. The distinguishing features of microfluidics have made the on‐chip reactor a highly efficient platform for general chemical experiments, especially catalysis. In this paper, through a brief review of the recent work on microfluidic catalysis, we highlight the importance of on‐chip catalytic microreactors. New approaches to the fabrication of on‐chip catalytic microreactors and their integration with multifunctional components are briefly introduced. Finally, the current challenges and future perspectives of this up‐and‐coming field are discussed based on our own opinions. It is believed that, with the progress of interdisciplinary cooperation, microfluidics and catalysis could be complementary sciences; catalysts may play a very important role in LoC systems, and on‐chip catalytic microreactors could be a highly efficient experimental platform for modern catalysis research.

Self-organization of polymer nanoneedles into large-area ordered flowerlike arrays

Combination of top-down and bottom-up process is crucial for fabricating ordered complex micronanostructures. Here we report a simple, rapid, and versatile approach to demonstrate this useful concept, which involves the joint use of multibeam interference patterning and capillary force self-organization. Regular hydrophobic arrays of four-peddle nanoflowers consisting of bent needles with 300 nm tip diameters are readily produced. A “domino model” based on the balance of the capillary and support forces were proposed to interpret realization of large-area homogeneity of the array. The technology, promising for preparing more complex and functional structures, may find broad utilization in nano and biological researches.

Rapid production of large-area deep sub-wavelength hybrid structures by femtosecond laser light-field tailoring

The goal of creation of large-area deep sub-wavelength nanostructures by femtosecond laser irradiation onto various materials is being hindered by the limited coherence length. Here, we report solution of the problem by light field tailoring of the incident beam with a phase mask, which serves generation of wavelets. Direct interference between the wavelets, here the first-order diffracted beams, and interference between a wavelet and its induced waves such as surface plasmon polariton are responsible for creation of microgratings and superimposed nanogratings, respectively. The principle of wavelets interference enables extension of uniformly induced hybrid structures containing deep sub-wavelength nanofeatures to macro-dimension.

Customization of Protein Single Nanowires for Optical Biosensing

An all-protein single-nanowire optical biosensor is constructed by a facile and general femtosecond laser direct writing approach with nanoscale structural customization. As-formed protein single nanowires show excellent optical properties (fine waveguiding performance and bio-applicable transmission windows), and are utilized as evanescent optical nanobiosensors for label-free biotin detection.