Bio-Inspired Screwed Conduits from the Microfluidic Rope-Coiling Effect for Microvessels and Bronchioles

Tubular microfibers have recently attracted extensive interest for applications in tissue engineering.However,the fabrication of tubular fibers with intricate hierarchical structures remains a major challenge.Here,we present a novel one-step microfluidic spinning method to generate bio-inspired screwed conduits(BSCs).Based on the microfluidic rope-coiling effect,a viscous hydrogel precursor is first curved into a helix stream in the channel,and then consecutively packed as a hollow structured stream and gelated into a screwed conduit(SC)via ionic and covalent crosslinking.By taking advantage of the excellent fluid-controlling ability of microfluidics,various tubes with diverse structures are fabricated via simple control over fluid velocities and multiple microfluidic device designs.The perfusability and permeability results,as well as the encapsulation and culture of human umbilical vein endothelial cells(HUVECs),human pulmonary alveolar epithelial cells(HPAs),and myogenic cells(C2C12),demonstrate that these SCs have good perfusability and permeability and the ability to induce the formation of functional biostructures.These features support the uniqueness and potential applications of these BSCs as biomimetic blood vessels and bronchiole tissues in combination with tissue microstructures,with likely application possibilities in biomedical engineering.

Sustainable biomedical microfibers from natural products

Microfibers from natural products are endowed with remarkable biocompatibility,biodegradability,sustainable utilization as well as environmental protection char-acteristics etc.Benefitting from these advantages,microfibers have demonstrated their prominent values in biomedical applications.This review comprehensively summarizes the relevant research progress of sustainable microfibers from natural products and their biomedical applications.To begin,common natural elements are introduced for the microfiber fabrication.After that,the focus is on the specific fabri-cation technology and process.Subsequently,biomedical applications of sustainable microfibers are discussed in detail.Last but not least,the main challenges during the development process are summarized,followed by a vision for future development opportunities.

The single-cell landscape reveals unique tumor subsets and microenvironments associated with poor clinical outcomes in primary testicular diffuse large B-cell lymphoma

Diffuse large B cell lymphoma(DLBCL)is one of the most prevalent lymphoid malignancies.The current standard of care can cure about two-thirds of DLBCL patients.1 Primary testicular diffuse large B-cell lymphoma(PT-DLBCL)is a rare but highly aggressive form of mature B-cell lymphoma that accounts for approximately 1%-9%of testicular malignancies.Different from nodal DLBCL,PT-DLBCL has a markedly worse prognosis because of inferior response to the current treatment regimens and significant extranodal tropism.2 Three main questions remained unresolved in the field of PT-DLBCL research.

Efficiency-oriented vehicle relocation of shared autonomous electric fleet in station-based car-sharing system

Long waiting delays for users and significant imbalances in vehicle distribution are bothering traditional station-based one-way electric car-sharing system operators.To address the problems above,a“demand forecast-station status judgement-vehicle relocation”multistage dynamic relocation algorithm based on the automatic formation cruising technology was proposed in this study.In stage one,a novel trip demand forecast model based on the long short-term memory network was established to predict users'car-pickup and car-return order volumes at each station.In stage two,a dynamic threshold interval was determined by combining the forecast results with the actual vehicle distribution among stations to evaluate the status of each station.Then vehicle-surplus,vehicleinsufficient,vehicle-normal stations,and the number of surplus or insufficient vehicles for each station were counted.In stage three,setting driving mileage and carbon emission as the optimization objectives,an integer linear programming mathematical model was constructed and the optimal vehicle relocation scheme was obtained by the commercial solver Gurobi.Setting 43 stations and 187 vehicles in Jiading District,Shanghai,China,as a case study,results showed that rapid vehicle rebalancing among stations with minimum carbon emissions could be realized within 15 min and the users’car-pickup and car-return demands could be fully satisfied without any refusal.

Hierarchical Spinning of Janus Textiles with Anisotropic Wettability for Wound Healing

Wound healing and tissue repair are recognized as basic human health problems worldwide.Attempts to accelerate the reparative process are focused on developing functional wound dressings.Herein,we present novel Janus textiles with anisotropic wettability from hierarchical microfluidic spinning for wound healing.The hydrophilic hydrogel microfibers from microfluidics are woven into textiles for freeze-drying treatment,followed by the deposition of electrostatic spinning nanofibers composed of hydrophobic polylactic acid(PLA)and silver nanoparticles.The electrospun nanofiber layer can be well coupled with the hydrogel microfiber layer to generate Janus textiles with anisotropic wettability due to the roughness of the hydrogel textile surface and the incomplete evaporation of PLA solution when reaching the surface.For wound treatment with the hydrophobic PLA side contacting the wound surface,the wound exudate can be pumped from the hydrophobic to the hydrophilic side based on the wettability differential derived drainage force.During this process,the hydrophobic side of the Janus textile can prevent excess fluid from infiltrating the wound again,preventing excessive moisture and preserving the breathability of the wound.In addition,the silver nanoparticles contained in the hydrophobic nanofibers could impart the textiles with good antibacterial effect,which further promote the wound healing efficiency.These features indicate that the described Janus fiber textile has great application potential in the field of wound treatment.

Frog tongue-inspired wettable microfibers for particles capture

Fibers have been of great significance in our daily lives,especially in the industrial production of masks.Research in this area has been focused on developing microfibers with superior functions to enhance the filtration performances of the masks.Herein,inspired by the frog’s predation mechanism using its tongues to swiftly grab flying insects,we propose novel porous wettable microfibers from microfluidics to efficiently capture particles in the air for filtration.Upon pre-dispersing LP emulsions into polyurethane(PU),porous microfibers dispersed with oil droplets could be continuously spun from a co-flow microfluidic device based on the quick phase inversion of PU.To design an optimal system with frog-tongue-like interfacial adhesion properties,the wettability performances of the porous microfibers are investigated under full,partial,and no oil coverage conditions.When implemented in a mask,the 3D patterned networks based on the frog-tongue-inspired microfibers have been proven with remarkable particle capture performances while maintaining good air permeability.Based on these features,we believe that frog-tongue-inspired microfibers and their derived masks are of practical significance in multiple applications.

Revisiting Dipole-Induced Fluorinated-Anion Decomposition Reaction for Promoting a LiF-Rich Interphase in Lithium-Metal Batteries

Building anion-derived solid electrolyte interphase(SEI)with enriched LiF is considered the most promising strategy to address inferior safety features and poor cyclability of lithium-metal batteries(LMBs).Herein,we discover that,instead of direct electron transfer from surface polar groups to bis(trifluoromethanesulfonyl)imide(TFSI-)for inducing a LiF-rich SEI,the dipole-induced fluorinated-anion decomposition reaction begins with the adsorption of Li ions and is highly dependent on their mobility on the polar surface.To demonstrate this,a single-layer graphdiyne on MXene(sGDY@MXene)heterostructure has been successfully fabricated and integrated into polypropylene separators.It is found that the adsorbed Li ions connect electron-donating sGDY@MXene to TFSI-,facilitating interfacial charge transfer for TFSI-decomposition.However,this does not capture the entire picture.The sGDY@MXene also renders the adsorbed Li ions with high mobility,enabling them to reach optimal reaction sites and expedite their coordination processes with O on O=S=O and F on the broken–CF_3~-,facilitating bond cleavage.In contrast,immobilized Li ions on the more lithiophilic pristine MXene retard these cleavage processes.Consequently,the decomposition reaction is accelerated on sGDY@MXene.This work highlights the dedicate balance between lithiophilicity and Li-ion mobility in effectively promoting a LiF-rich SEI for the long-term stability of LMBs.

Liquid metal-integrated ultra-elastic conductive microfibers from microfluidics for wearable electronics

Liquid metal(LM) has shown potential values in different areas. Attempts to implement LM are tending to develop new functions and make it versatile to improve its performance for practical applications.Here, we present an unprecedented LM-integrated ultra-elastic microfiber with distinctive features for wearable electronics. The microfiber with a polyurethane shell and an LM core was continuously generated by using a sequenced microfluidic spinning and injection method. Due to the precise fluid manipulation of microfluidics, the resultant microfiber could be tailored with tunable morphologies and responsive conductivities. We have demonstrated that the microfiber could act as dynamic force sensor and motion indicator when it was embedded into elastic films. In addition, the values of the LMintegrated ultra-elastic microfiber on energy conversions such as electro-magnetic or electro-thermal conversions have also been realized. These features indicate that LM-integrated microfiber will open up new frontiers in LM-integrated materials and the wearable electronics field.

Tailoring micro/nano-fibers for biomedical applications

Nano/micro fibers have evoked much attention of scientists and have been researched as cutting edge and hotspot in the area of fiber science in recent years due to the rapid development of various advanced manufacturing technologies,and the appearance of fascinating and special functions and properties,such as the enhanced mechanical strength,high surface area to volume ratio and special functionalities shown in the surface,triggered by the nano or micro-scale dimensions.In addition,these outstanding and special characteristics of the nano/micro fibers impart fiber-based materials with wide applications,such as environmental engineering,electronic and biomedical fields.This review mainly focuses on the recent development in the various nano/micro fibers fabrication strategies and corresponding applications in the biomedical fields,including tissue engineering scaffolds,drug delivery,wound healing,and biosensors.Moreover,the challenges for the fabrications and applications and future perspectives are presented.

Morphological Hydrogel Microfibers with MXene Encapsulation for Electronic Skin

Electronic skins with distinctive features have attracted remarkable attention from researchers because of their promising applications in flexible electronics.Here,we present novel morphologically conductive hydrogel microfibers with MXene encapsulation by using a multi-injection coflow glass capillary microfluidic chip.The coaxial flows in microchannels together with fast gelation between alginate and calcium ions ensure the formation of hollow straight as well as helical microfibers and guarantee the in situ encapsulation of MXene.The resultant hollow straight and helical MXene hydrogel microfibers were with highly controllable morphologies and package features.Benefiting from the easy manipulation of the microfluidics,the structure compositions and the sizes of MXene hydrogel microfibers could be easily tailored by varying different flow rates.It was demonstrated that these morphologically conductive MXene hydrogel microfibers were with outstanding capabilities of sensitive responses to motion and photothermal stimulations,according to their corresponding resistance changes.Thus,we believe that our morphologically conductive MXene hydrogel microfibers with these excellent features will find important applications in smart flexible electronics especially electronic skins.

Data quality issues for synchrophasor applications PartⅠ:a review

Synchrophasor systems, providing low-latency,high-precision, and time-synchronized measurements to enhance power grid performances, are deployed globally.However, the synchrophasor system as a physical network,involves communication constraints and data quality issues, which will impact or even disable certain synchrophasor applications. This work investigates the data quality issue for synchrophasor applications. In Part I, the standards of synchrophasor systems and the classifications and data quality requirements of synchrophasor applications are reviewed. Also, the actual events of synchronization signal accuracy, synchrophasor data loss, and latency are counted and analyzed. The review and statistics are expected to provide an overall picture of data accuracy,loss, and latency issues for synchrophasor applications.

Microfluidic Generation of Microsprings with Ionic Liquid Encapsulation for Flexible Electronics

Inspired by helical or spiral veins,which endow plants with excellent fexibility and elasticity to withstand storms,we present novel hollow microsprings with ionic liquid encapsulation for fexible and stretchable electronics.Te microsprings were generated by using a coaxial capillary microfuidic device to consecutively spin poly(vinylidene fuoride)(PVDF)presolution and an ionic liquid,which formed laminar fows in the coaxial injection microfuidic channels.Te fast phase inversion of PVDF helps to form the core-shell structure of a microfber and guarantees the in situ encapsulation of ionic liquid.Te hybrid microfber can then spiral and be further solidifed to maintain the helical structure with increasing fow rates of the injection fuids.Because of the feasible and precise control of the injection fuids during the microfuidic spinning,the resultant microsprings have controlled core-shell structures,helical pitches,and corresponding electromechanical properties.By further embedding them into stretchable flms,the simple paradigm of a fexible device shows great conductive performance in tensile tests and even motion cycles,which could be explored as a promising candidate in stretchable sensors,fexible electronics,and electronic skins.

Insight into sulfur and iron effect of binary nickel-iron sulfide on oxygen evolution reaction

Nickel-iron sulfide has shown attractive activity in electrocatalytic oxygen evolution reaction(OER).However,the effects of low valence sulfur(S^(2−))and metal species on OER in binary nickel-iron sulfide have rarely been systematically studied.Works based on post-catalysis characterization have led to the assumption that the real active species are nickel-iron oxyhydroxide,and that nickel-iron sulfide acts only as a precatalyst.Therefore,to study the role of S,Ni,and Fe for the development of nickel-iron sulfide catalyst is of self-evident importance.Herein,a facile solvothermal method is used to synthesize acetylene black coated with nickel-iron sulfide nanosheets.Electrochemical tests show that the presence of low valence S species makes the catalyst have faster OER kinetics,larger active area,and intermediate active species adsorption area.Therefore,the present study reveals the enhancing effect of low valence sulfur species(S^(2−))on OER in binary nickel-iron sulfide.In situ Raman spectroscopy shows that the generation ofγ-NiOOH intermediate is essential and Fe does not directly participate in the oxygen production.Density functional theory(DFT)calculation shows that Ni-OH deprotonation is a rate-determining step for both binary nickel-iron sulfide and nickel sulfide.The addition of Fe into NiSx lightly increases the charge transfer of Ni atom to O atom,which makes deprotonation easier and thereby improves the OER performance.

Bamboo‑Inspired Gasotransmitter Microfibres for Wound Healing

Diabetic wounds have become a major clinical problem that cannot be ignored.Gases,such as hydrogen sulphide(H_(2)S),have demonstrated value in inducing angiogenesis and accelerating wound healing,while their effective delivery is still challenging.Here,inspired by the continuous-independent hollow structure of bamboo,we propose novel gasotransmitter microfibres with septal H_(2)S bubbles using microfluidic spinning for diabetic wound healing.Benefitting from the exact control of microfluidics,gasotransmitter microfibres with different bubble sizes and morphologies could be generated successfully and continuously.Under the dual effects of drugs in the shell and gas in the core,the wound healing process could be accelerated.Furthermore,the controllable release of drugs could be achieved by adding responsive materials into the microfiber shell,which would promote continuous effects of contents on demand.Based on in vitro and in vivo stud-ies,we have proven that these gasotransmitter microfibres have a positive impact on inducing angiogenesis and promoting cell proliferation during wound healing.Thus,it is believed that the bamboo-inspired gasotransmitter microfibres will have important value in gasotransmitter research and clinical applications.

Pollens derived magnetic porous particles for adsorption of low-density lipoprotein from plasma

Adsorption of low-density lipoprotein from plasma is vital for the treatment of dyslipidemia.Appropriate adsorbent material for efficient and selective adsorption of low-density lipoprotein is highly desired.In this work,we developed pollens-derived magnetic porous particles as adsorbents for this purpose.The natural pollen grains were modified to obtain high surface porosity,a large inner cavity,magnet responsiveness,and specific wettability.The resultant particles exhibited satisfying performance in the adsorption of a series of oils and organic solvents out of water.Besides,the particles were directly utilized to the adsorption of low-density lipoprotein in plasma,which showed high selectivity,and achieved an outstanding adsorption capacity as high as 34.9%within 2 h.Moreover,their salient biocompatibility was demonstrated through simulative hemoperfusion experiments.These features,together with its abundant source and facile fabrication,makes the pollens-derived magnetic porous particles excellent candidate for low-density lipoprotein-apheresis and water treatment applications.

导电微纤维的微流控制备及其在柔性电子领域的应用

柔性电子是一种新兴的电子技术.近年来,随着电子材料研究的深入,柔性电子已成功地与多个学科领域结合,成为跨学科研究的热门领域之一.与传统的刚性电子产品相比,柔性电子在轻便性、生物相容性、可穿戴性、机械稳定性和灵活性等方面展现出极大的优势.而纤维材料作为柔性电子系统的基础结构之一,其具有质量轻、机械柔韧性好、功能性多样的优点,在柔性电子膜、纺织品、可穿戴设备等多个行业中发挥着重要作用.在多种纤维制备方式中,微流控可以实现对微通道流体的精准操控,被证实可以实现多样化结构微纤维的制备.随着理论研究的深入和技术工艺的革新,微流控技术被认为是一种经济而有力的用于制造柔性导电微纤维的工具,并推动了其在柔性电子器件如传感器、储能器等方面的应用.因此,本文首先总结微流控纺丝技术在导电微纤维制备领域的研究进展,包括实心结构、核壳结构及多组分结构微纤维的制备;然后,重点介绍导电微纤维在传感、能量存储、组织工程等柔性电子领域的应用进展;最后,针对导电纤维用于柔性电子领域将面临的挑战和发展方向进行展望.

Bioinspired perovskite quantum dots microfibers from microfluidics

As perovskite quantum dots(PeQDs)are performing their outstanding characteristics,incremental efforts have been devoted to such materials.Here,inspired by the spider spinning process,we present novel PeQDs microfibers with tailorable morphologies and functions from a multi-injection microfluidic approach.The microfibers were generated by introducing PeQDs precursors into each barrel of the inner capillary array and mixing them in the spindle middle channel,where the poly(vinylidene fluoride)(PVDF)dissolved in N,N-dimethyl formamide(DMF)was also injected as their sheath fluid.During this process,the PeQDs were in situ synthesized with the connection of precursor cations and anions in the core fluid;while the PVDF formed solidified microfibers to encapsulate PeQDs with the fast dispersion of DMF into the outer aqueous solution.Thus,the good encapsulation of PeQDs was achieved in PVDF microfibers,which effectively protected them from different hostile environments.Because of the highly tunable spinning processes,the microfibers exhibited controllable diameters and helical geometric structures,and the encapsulated PeQDs could yield adjustable emission peaks.Based on the PeQDs microfibers,we have explored their potential as luminescent materials in barcodes and as flexible photodetectors,which make such microfibers highly versatile for different areas.

Shear-flow-induced graphene coating microfibers from microfluidic spinning

The advancements in flexible electronics call for invention of fiber-based electronic systems by surface modification or encapsulation.Here we present novel shear-flow-induced graphene nanosheets coating microfibers by integrating the dip coating approach with the microfluidic spinning method.The core hydrogel microfiber was first spun continuously from the microfluidic device,and the shear flow from the dip coating approach allowed formation of the thin graphene oxide(GO)nanosheet coating shell.

Jellyfish Tentacle‑Inspired Hydrogel Microfibers Implanted with Discrete Structural Color Microsphere Tactile Sensing Units

Tactile sensors with distinctive ability to imitate skins have attracted considerable attention from researches for applications in a variety of sensing fields.Here,inspired by the tentacles of jellyfish,biomimetic hydrogel microfibers were fabricated to be implanted with discrete structural color microsphere units for spatial tactile sensing.By employing a microfluidic spinning technology,the generated microfibers were with high microsphere encapsulation features and controllable morphologies because of the density match of microspheres and the pre-hydrogel solution.In addition,benefitting from the easy manipulation of the microfluidics,microfibers implanted with different structural color microspheres could also be realized.It was demonstrated that the resultant microfibers would show synchronous shifts of photonic bandgaps as well as structural color when a local force like pressure or tension was applied to the microsphere part.Based on the localization of finger bending experiments,the practical values of the bioinspired microfibers have also been proved as spatial tactile sensors.Thus,it is believed that the proposed bioinspired hydrogel microfibers are greatly significant in diverse sensing application fields.