A review on current development of thermophotovoltaic technology in heat recovery

The burning of fossil fuels in industry results in significant carbon emissions,and the heat generated is often not fully utilized.For high-temperature industries,thermophotovoltaics(TPVs)is an effective method for waste heat recovery.This review covers two aspects of high-efficiency TPV systems and industrial waste heat applications.At the system level,representative results of TPV complete the systems,while selective emitters and photovoltaic cells in the last decade are compiled.The key points of components to improve the energy conversion efficiency are further analyzed,and the related micro/nano-fabrication methods are introduced.At the application level,the feasibility of TPV applications in high-temperature industries is shown from the world waste heat utilization situation.The potential of TPV in waste heat recovery and carbon neutrality is illustrated with the steel industry as an example.

Blade-Coated Porous 3D Carbon Composite Electrodes Coupled with Multiscale Interfaces for Highly Sensitive All-Paper Pressure Sensors

Flexible and wearable pressure sensors hold immense promise for health monitoring,covering disease detection and postoperative rehabilitation.Developing pressure sensors with high sensitivity,wide detection range,and cost-effectiveness is paramount.By leveraging paper for its sustainability,biocompatibility,and inherent porous structure,herein,a solution-processed all-paper resistive pressure sensor is designed with outstanding performance.A ternary composite paste,comprising a compressible 3D carbon skeleton,conductive polymer poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate),and cohesive carbon nanotubes,is blade-coated on paper and naturally dried to form the porous composite electrode with hierachical micro-and nano-structured surface.Combined with screen-printed Cu electrodes in submillimeter finger widths on rough paper,this creates a multiscale hierarchical contact interface between electrodes,significantly enhancing sensitivity(1014 kPa-1)and expanding the detection range(up to 300 kPa)of as-resulted all-paper pressure sensor with low detection limit and power consumption.Its versatility ranges from subtle wrist pulses,robust finger taps,to large-area spatial force detection,highlighting its intricate submillimetermicrometer-nanometer hierarchical interface and nanometer porosity in the composite electrode.Ultimately,this all-paper resistive pressure sensor,with its superior sensing capabilities,large-scale fabrication potential,and cost-effectiveness,paves the way for next-generation wearable electronics,ushering in an era of advanced,sustainable technological solutions.

CURRENT TRENDS OF MICRO-AND NANOMECHANICS

Introduction Scaling down to the micro- and nanoscale is a strong current trend in the development of science and technology. ＇Small is energy efficient and cost effective＇ has long been for the motto of the semiconductor industry, including micro- and nanoelectronics, micro-electro-mechanical systems （MEMS） and nanoelectro-mechanical systems （NEMS）.

Pushing the frontiers: Chip-based detection based on micro-and nano-structures

Changes in trace substances in human metabolites, which are related to disease processes and health status, can serve as chemical markers for disease diagnosis and symptom monitoring. Real-time online detection is an inevitable trend for the future of health monitoring, and the construction of chips for detection faces major challenges. The response of sensors often fails to meet the requirements for chipbased detection of trace substances due to the low efficiency of interfacial heterogeneous reactions, necessitating a rational design approach for micro-and nano-structures to improve sensor performance with respect to sensitivity and detection limits. This review focuses on the influence of micro-and nanostructures that used in chip on sensing. Firstly, this review categorizes sensors into chemiresistors, electrochemical sensors, fluorescence sensors, and surface enhanced Raman scattering(SERS) sensors based on their sensing principle, which have significant applications in disease diagnosis. Subsequently, commencing from the application requirements in the field of sensing, this review focuses on the different structures of nanoparticle(NP) assemblies, including wire, layered, core-shell, hollow, concave and deformable structures. These structures change in the size, shape, and morphology of conventional structures to achieve characteristics such as ordered alignment, high specific surface area, space limitation,vertical diffusion, and swaying behavior with fluid, thereby addressing issues such as poor signal transmission efficiency, inadequate adsorption and capture capacity, and slow mass transfer speed during sensing. Finally, the design direction of micro-and nano-structures, and possible obstacles and solutions to promote chip-based detection have been discussed. It is hope that this article will inspire the exploration of interface micro-and nano-structures modulated sensing methods.

Mechanical Properties of Micro-regions in Cement-based Material based on the PeakForce QNM Mode of AFM

In this paper, the cement paste and the mortar were tested using the PF-QNM technique. It is shown that the PF-QNM technique is very powerful to characterize the mechanical properties of micro-and nanostructures in the cement-based materials. It does not have strict requirements for test environment and it does not damage the surface of the material. High-resolution images can be obtained very easily, and they can be analyzed statistically. The test results show that PF-QNM analysis can test not only the mechanical properties of the cement paste, but also investigate the interfacial regions in the cement-based material, including the variation in the mechanical properties of interface regions and the extension of the interfacial regions. During the test, care must be taken to choose the size of test area;indeed, a test area too small is not representative but too large leads to lack of stability. The recommended side is a square with a length of in the range 10-30 μm.

Wettability Pattern for Ultrafast Water Self‑Pumping on Cemented Carbide Surface

A facile method to fabricate wettability pattern(two extreme wettabilities arranged in a pattern)to realize water self-pumping is proposed on cemented carbide while not necessarily depositing other materials on substrate surface.The water self-pumping is achieved by arranging wedge shaped superhydrophilic domain in superhydrophobic substrate using laser machining.Through single factor experiments,it is found that the key to the extreme wettabilities,micro⁃and nano⁃structures,is rendered by laser machining processes and is influenced by laser parameters.Meanwhile,the proper laser parameters that are used to fabricate required micro-and nano⁃structures are obtained.Finally,the water transport experiment is carried out,which shows that the velocity of water bulge could be up to 362 mm/s when the wedge angle is 3°.The mechanism of the water self-pumping is analyzed and it is found that the migration of water bulge is governed by Laplace pressure of the water bulge induced by the wedge micro-groove.

高分子薄膜中异质含氟表面的宏观、微观和纳米结构及应用（英文）

INTRODUCTION Recently,in polymer technology,there has been an evident change in the production of flexible functional film materials and devices on flexible polymer substrates.The aforementioned products are used in power engineering(light-emitting materials,solar cells),medicine(materials with incorporated drugs and other special ingredients,functionalized membranes,medical transdermal films),

Medical micro-and nanomotors in the body

Attributed to the miniaturized body size and active mobility,micro-and nanomotors(MNMs)have demonstrated tremendous potential for medical applications.However,from bench to bedside,massive efforts are needed to address critical issues,such as cost-effective fabrication,on-demand integration of multiple functions,biocompatibility,biodegradability,controlled propulsion and in vivo navigation.Herein,we summarize the advances of biomedical MNMs reported in the past two decades,with particular emphasis on the design,fabrication,propulsion,navigation,and the abilities of biological barriers penetration,biosensing,diagnosis,minimally invasive surgery and targeted cargo delivery.Future perspectives and challenges are discussed as well.This review can lay the foundation for the future direction of medical MNMs,pushing one step forward on the road to achieving practical theranostics using MNMs.

Dependence of Gravity Induced Absorption Changes on the Earth’s Magnetic Field as Measured during Parabolic Flight Campaigns

Various spectroscopic experiments performed on the AIRBUS ZERO G—located in Bordeaux, France—in the years 2002 to 2012 exhibit minute optical reflection/absorption changes (GIACs) as a result of gravitational changes between 0 and 1.8 g in various biological species such as maize, oats, Arabidopsis and particularly Phycomyces sporangiophores. During a flight day, the AIRBUS ZERO G conducts 31 parabolas, each of which lasts about three minutes including a period of 22 s of weightlessness. So far, we participated in 11 parabolic flight campaigns including more than 1000 parabolas performing various kinds of experiments. During our campaigns, we observed an unexplainable variability of the measuring signals (GIACs). Using GPS-positioning systems and three dimensional magnetic field sensors, these finally were traced back to the changing earth’s magnetic field associated with the various flight directions. This is the first time that the interaction of gravity and the Earth’ magnetic field in the primary induction process in living system has been observed.

Flexible nanoimprint lithography enables high-throughput manufacturing of bioinspired microstructures on warped substrates for efficient III-nitride optoelectronic devices

III-nitride materials are of great importance in the development of modern optoelectronics,but they have been limited over years by low light utilization rate and high dislocation densities in heteroepitaxial films grown on foreign substrate with limited refractive index contrast and large lattice mismatches.Here,we demonstrate a paradigm of high-throughput manufacturing bioinspired microstructures on warped substrates by flexible nanoimprint lithography for promoting the light extraction capability.We design a flexible nanoimprinting mold of copolymer and a two-step etching process that enable high-efficiency fabrication of nanoimprinted compound-eye-like Al2O3 microstructure(NCAM)and nanoimprinted compound-eye-like SiO_(2)microstructure(NCSM)template,achieving a 6.4-fold increase in throughput and 25%savings in economic costs over stepper projection lithography.Compared to NCAM template,we find that the NCSM template can not only improve the light extraction capability,but also modulate the morphology of AlN nucleation layer and reduce the formation of misoriented GaN grains on the inclined sidewall of microstructures,which suppresses the dislocations generated during coalescence,resulting in 40%reduction in dislocation density.This study provides a low-cost,high-quality,and high-throughput solution for manufacturing microstructures on warped surfaces of III-nitride optoelectronic devices.

Atomic-level unveiling secondary recrystallization enabled microand macroscopic polarization enhancement for piezophotocatalytic oxygen activation

Piezoelectric semiconductors bear the bifunctional photocatalysis and piezocatalysis,while the absent or weak internal charge driving force severely restricts its catalytic activity.Developing polarization strategy is desirable,and particularly understanding its mechanism from a microscopic perspective remains scanty.Herein,we report a secondary recrystallization approach to achieving the simultaneous micro-and macroscopic polarization enhancement on Bi2WO6 nanosheets for boosting piezo-photocatalytic oxygen activation,and unravel the mechanism at an atom-level.The secondary recrystallization process not only results in a strengthened distortion of[WO6]octahedra with distortion index enhancement by~20%for a single octahedron,but also enables lateral crystal growth of nanosheets along the ab plane(av.50 to 180 nm),which separately allows the rise in dipole moment of unit cell(e.g.,1.63 D increase along a axis)and the stacking of the distorted[WO6]octahedron to accumulate the unit cell dipole,collectively contributing to the considerably strengthened spontaneous polarization and piezoelectricity.Besides,exposure of large-area{001}front facet enables more efficient capture and conversion of stress into piezo-potential.Therefore,the well-recrystallized Bi2WO6 nanosheets exhibit considerably promoted piezo-photocatalytic reactive oxygen species generation,given the decreased specific surface area.This work presents a feasible methodology to regulate inside-out polarization for guiding carriers transfer behavior,and may advance the solid understanding on the intrinsic mechanism.

Micro-and submicrostructural evidence for high-temperature brittle-ductile transition deformation of hornblende: Case study of high-grade mylonites from Diancangshan, western Yunnan

OM (optical microscope)/TEM (transmission electron microscope) micro- and submicrostructural analysis of hornblende rocks sheared at high temperatures from the Diancangshan area, western Yunnan reveals evidence for deformation in the brittle-ductile transition of hornblende at middle crustal level (about 637℃ and 0.653 GPa) and mechanisms of deformation in the transitional regime are further discussed. Sheared hornblende rocks at middle crustal level have typical mylonitic microstructures, shown by coarse porphyroclasts and fine matrix grains. Different mineral phases in the rocks show distinct deformation characteristics. Hornblende and feldspar grains are intensely deformed with ob- vious grainsize reduction, but quartz grains are recrystallized dominantly by grain growth. Hornblende grains show typical brittle-ductile transition nature. Initial crystallographic orientations of porphyro- clasts have strong effects on the behavior of grains during deformation. There are mainly two types of porphyroclasts, type I "hard" porphyroclasts and type II "soft" porphyroclasts, with [001] perpendicular and parallel to external shear stresses respectively. "Hard" porphyroclasts generally occur as compe- tent grains that are rarely deformed or sometimes deformed by fracturing and dislocation tangling. "Soft" porphyroclasts are highly deformed primarily by dislocation tangling (as shown in the cores of the porphyroclasts), but twinning, dislocation glide and climb probably due to hydrolytic weakening also contribute to dynamic recrystallization of the porphyroclasts into fine grains in the matrix. The micro- and submicrostructures of the two types of porphyroclasts and fine-grained matrix provide powerful evidence for the behavior of brittle-ductile transition of hornblende grains. It is concluded that twinning nucleation is one of the most important processes that operate during dynamic recrystalliza- tion of hornblende crystals at the brittle-ductile transition. (100) [001] twin gliding and dislocation creep (dislocation glide and climb) are mutually enhanced during twinning nucleation. As a newly discovered mechanism of dynamic recrystallization, it may have played more important roles than ever recognized during dynamic recrystallization of crystals with twins in the brittle-ductile transition.

Development of micro-and nanorobotics: A review

Micro-and nanorobotic is an emerging field of research arising from the cross-fusion of micro/nano technology and robotics and has become an important part of robotics. Micro-and nanorobots have the advantages of small size, low weight, large thrust-toweight ratio, high flexibility, and high sensitivity. Due to the characteristics distinguishing from macroscopic robots, micro-and nanorobots have stimulated the research interest of the scientific community and opened up numerous application fields such as drug delivery and disease diagnosis. In the past 30 years, research on micro-and nanorobots has made considerable progress.This article provides a comprehensive overview of the development of these robots. First, the application of the robots is reviewed. Then, the key components of the robots are discussed separately, covering their actuation, design, fabrication and control. In addition, from the perspectives of intelligence and sensing, clinical applications, materials and performance, the challenges that may be encountered in the development of such robots in the future are discussed. Finally, the entire article is summarized, and concepts for future micro-and nanorobots are described.

Superhydrophobicity on Micro-and Nanostructured Polyolefin Surfaces:an Experimental and Theoretical Study

1 Results Simultaneous micro-and nanostructuring was prepared on polyolefin surfaces by injection molding.The molds were made of electropolished aluminum foil where the micropatterns were structured with a custom made robot.Nanopatterns were subsequently created on the molds by oxidizing the aluminum surface electrochemically in polyprotic acid.The preparation technique allowed simultaneous control of the dimensions of the micro-and nanostructures.Structuring has a remarkable effect on the contact angle...

Real time full-color imaging in a Meta-optical fiber endoscope

Endoscopes are an important component for the development of minimally invasive surgeries.Their size is one of the most critical aspects,because smaller and less rigid endoscopes enable higher agility,facilitate larger accessibility,and induce less stress on the surrounding tissue.In all existing endoscopes,the size of the optics poses a major limitation in miniaturization of the imaging system.Not only is making small optics difficult,but their performance also degrades with downscaling.Meta-optics have recently emerged as a promising candidate to drastically miniaturize optics while achieving similar functionalities with significantly reduced size.Herein,we report an inverse-designed meta-optic,which combined with a coherent fiber bundle enables a 33%reduction in the rigid tip length over traditional gradient-index(GRIN)lenses.We use the meta-optic fiber endoscope(MOFIE)to demonstrate real-time video capture in full visible color,the spatial resolution of which is primarily limited by the fiber itself.Our work shows the potential of meta-optics for integration and miniaturization of biomedical devices towards minimally invasive surgery.

可定制多孔玻璃表面的溶解制造策略

玻璃表面微纳结构的设计和制造在实现所需功能方面具有重要意义.然而,玻璃固有的硬度和脆性给传统制造方法带来了不便.因此,开发一种简单且可控的制造策略对于制备具备功能应用的微纳结构玻璃至关重要.在本文中,我们提出了一种创新方法,利用可溶性氯化钠颗粒作为前驱体模板,在玻璃表面上创建可定制的多孔结构.通过我们的先导成型策略,成功利用可溶性氯化钠颗粒的潜力作为前驱体模板,从而便于制造量身定制的多孔玻璃表面.通过调节这些颗粒的大小和组合,我们实现了对所得多孔玻璃的连续调控,范围从超亲水(1°)到超疏水(142°).值得注意的是,制备的多孔玻璃表面表现出显著的亲油性,展示了在油水分离和自清洁等多种应用方面的巨大潜力.最重要的是,即使经过了10次制造迭代,玻璃表面的疏水-亲油功能依然完好,凸显了我们策略的耐久性和可重复性.这种方法为实现玻璃的特殊功能提供了方便且具有成本效益的途径,为不同领域的进展铺平了道路.

Bioinspired urease-powered micromotor as an active oral drug delivery carrier in stomach

Self-propelling micro-and nano-motors(MNMs)have been extensively investigated as an emerging oral drug delivery carrier for gastrointestinal(GI)tract diseases.However,the propulsion of current MNMs reported so far is mostly based on the redox reaction of metals(such as Zn and Mg)with severe propulsion gas generation,remaining non-degradable residue in the GI tract.Here,we develop a bioinspired enzyme-powered biopolymer micromotor mimicking the mucin penetrating behavior of Helicobacter pylori in the stomach.It converts urea to ammonia and the subsequent increase of pH induces local gel-sol transition of the mucin layer facilitating the penetration into the stomach tissue layer.The successful fabrication of micromotors is confirmed by high-resolution transmission electron microscopy,electron energy loss spectroscopy,dynamic light scattering analysis,zeta-potential analysis.In acidic condition,the immobilized urease can efficiently converted urea to ammonia,comparable with that of neutral condition because of the increase of surrounding pH during propulsion.After administration into the stomach,the micromotors show enhanced penetration and prolonged retention in the stomach for 24 h.Furthermore,histological analysis shows that the micromotors are cleared within 3 days without causing any toxicity in the GI tract.The enhanced penetration and retention of the micromotors as an active oral delivery carrier in the stomach would be successfully harnessed for the treatment of various GI tract diseases.

Manipulating Bloch surface waves in 2D: a platform concept-based flat lens

At the end of the 1970s,it was confirmed that dielectric multilayers can sustain Bloch surface waves(BSWs).However,BSWs were not widely studied until more recently.Taking advantage of their high-quality factor,sensing applications have focused on BSWs.Thus far,no work has been performed to manipulate and control the natural surface propagations in terms of defined functions with two-dimensional(2D)components,targeting the realization of a 2D system.In this study,we demonstrate that 2D photonic components can be implemented by coating an in-plane shaped ultrathin(l/15)polymer layer on the dielectric multilayer.The presence of the polymer modifies the local effective refractive index,enabling direct manipulation of the BSW.By locally shaping the geometries of the 2D components,the BSW can be deflected,diffracted,focused and coupled with 2D freedom.Enabling BSW manipulation in 2D,the dielectric multilayer can play a new role as a robust platform for 2D optics,which can pave the way for integration in photonic chips.Multiheterodyne near-field measurements are used to study light propagation through micro-and nano-optical components.We demonstrate that a lens-shaped polymer layer can be considered as a 2D component based on the agreement between near-field measurements and theoretical calculations.Both the focal shift and the resolution of a 2D BSW lens are measured for the first time.The proposed platform enables the design of 2D all-optical integrated systems,which have numerous potential applications,including molecular sensing and photonic circuits.

Precision in harsh environments

Microsystems are increasingly being applied in harsh and/or inaccessible environments,but many markets expect the same level of functionality for long periods of time.Harsh environments cover areas that can be subjected to high temperature,(bio)-chemical and mechanical disturbances,electromagnetic noise,radiation,or high vacuum.In the field of actuators,the devices must maintain stringent accuracy specifications for displacement,force,and response times,among others.These new requirements present additional challenges in the compensation for or elimination of cross-sensitivities.Many state-of-the-art precision devices lose their precision and reliability when exposed to harsh environments.It is also important that advanced sensor and actuator systems maintain maximum autonomy such that the devices can operate independently with low maintenance.The next-generation microsystems will be deployed in remote and/or inaccessible and harsh environments that present many challenges to sensor design,materials,device functionality,and packaging.All of these aspects of integrated sensors and actuator microsystems require a multidisciplinary approach to overcome these challenges.The main areas of importance are in the fields of materials science,micro/nano-fabrication technology,device design,circuitry and systems,(first-level)packaging,and measurement strategy.This study examines the challenges presented by harsh environments and investigates the required approaches.Examples of successful devices are also given.

PMMA-Based Microsphere Mask for Sub-wavelength Photolithography

The authors present a polymethyl methacrylate(PMMA)-based,reusable microsphere mask used in the laser sub-wavelength photolithography.In order to overcome the diffraction limit to achieve nano-structuring using l-|im laser wavelength,the photolithography technique was conventionally characterized by applying a one-off monolayer of silica microspheres serving as Mie scatterers.Addressing the major limitation of this technique,which was that the monolayer of microspheres must be prepared on the sample surface prior to fabrication,the proposed hot press approach could firmly fuse the 1silica microspheres to the PMMA base without the use of adhesives.The PMMA-based microsphere mask could hence reduce the amount of work for the monolayer preparation and was proven reusable for at least 20 times without damage to top or bottom surfaces.Using the mask,dimples that were 0.7 pm in diameter and 40 nm in depth were produced on tool steel by a single pulse of picosecond laser irradiation.