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4D printed shape memory polymers and their structures for biomedical applications

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Science China(Technological Sciences) 2020年第4期63卷 545-560页

作者： LI YueJia zhang fenghua LIU YanJu LENG JinSong National Key Laboratory of Science and Technology on Advanced Composites in Special Environment Harbin Institute of Technology(HIT)Harbin 150080China Department of Astronautical Science and Mechanics Harbin Institute of Technology(HIT)Harbin 150001China

Shape memory polymers are smart materials that produce shape changes under external stimulus ***-dimensional(4D)printing is a comprehensive technology originate from deformable materials and three-dimensional(3D)printing *** present,4D printed shape memory polymers and shape-changing structures have been applied in various fields,especially in the field of biomedical science.4D printing technology has made a breakthrough of personalized customization in the traditional medical field,providing a new direction for the further development of the biomedical *** this review,the recent research and development of shape memory polymer,3D printing technology,4D printed shape memory polymers and shape-changing structures in biomedical area are *** examples and applications of 4D printed shape memory polymers and their structures in the area of biomedical are also *** on 4D printing,stimulated by different conditions,3D printed objects can be fabricated into various biomedical applications such as cell scaffolds,vascular stents,bone scaffolds,tracheal stents and cardiac stents by different 3D printing ***,the application prospects,existing technical restriction and future development directions of 4D printed shape memory polymers and their structures in the biomedical field are summarized.

关键词： 4D printing shape memory polymers shape-changing structures biomedical applications

Advances in 4D printed shape memory composites and structures:Actuation and application

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Science China(Technological Sciences) 2023年第5期66卷 1271-1288页

作者： WANG LinLin zhang fenghua DU ShanYi LENG JinSong Centre for Composite Materials and Structures Harbin Institute of Technology(HIT)Harbin 150080China

Shape memory polymer composites(SMPCs)are a type of smart material that can change shapes under the stimulation of the external environment,and they have great potential in aerospace,biomedical,robotics,and electronic devices due to their advantages of high strength and toughness,lightweight,impact resistance,corrosion resistance,and aging resistance.4D printing technology has provided new opportunities for the further development of smart *** addition of various fillers enriches the variety of printable materials and provides composites with different properties and *** combination of SMPCs and printing technologies realizes the structure-function *** paper introduces the emergence and development of 4D printing technologies,the preparation methods and properties of SMPCs for 4D printing;as well as the research progress and potential application of 4D printable SMPCs in recent years in terms of thermal,electrical,magnetic,and optical ***,the existing problems and future development of 4D printable SMPCs are discussed.

关键词： shape memory polymer composites 4D printing deformable structures actuation modes applications

Experimental Investigation on Noise of Cavitation Nozzle and Its Chaotic Behaviour

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Chinese Journal of Mechanical Engineering 2013年第4期26卷 758-762页

作者： zhang fenghua LIU Haifeng XU Junchao TANG Chuanlin School of Mechanical Engineering Hunan University of Technology

The researches of cavitation noise mainly focus on the incipiency and developing of cavitation to prevent the cavititation erosion in the hydraulic machinery, while there is few report about the collapse strength of cavitation bubbles produced by water jet through the cavitation nozzle to utilize efficiently the collapse energy of cavitation bubbles. The cavitation noise signals are collected with hydrophones for the cavitation nozzle and general nozzle at the target position and the nozzle exit separately in the conditions of different standoff distance. The features of signal’s frequency spectrum and power spectrum are analyzed for various nozzles by way of classical methods. Meanwhile, based on chaotic theory, phase space reconstruction is processed and the maximum Lyapunov index is calculated separately for each cavitation signal’s time series. The results of chaotic analysis are compared with the one of conventional analysis. The analyzed data show that there are the marked differences at the spectrum between the cavitation nozzle and general nozzle at the target position while the standoff distance is 35 mm, which mainly displays at the high frequency segment (60-120 kHz). The maximum Lyapunov index calculated appear at standoff distance 35 mm, which is an optimum standoff distance for the most bubbles to collapse at the target. At the nozzle exit, the noise signal of cavitation nozzle is different from the general nozzle, which also displays at the high frequency segment. The results demonstrate that the water jet modulated by the cavitation nozzle can produce effectually cavitation, and at the target position the amplitude and energy of noise spectrum in high frequency segment for cavitation nozzle are higher than conventional nozzle and the Lyapunov index of cavitation nozzle is larger than conventional nozzle as the standoff distance is less than 55 mm. The proposed research reveals that the cavitation noise produced by collapse of cavitation bubbles attri

关键词： cavitation water jet nozzle Lyapunov exponent chaos

Shape Memory Polymer Fibers:Materials,Structures,and Applications

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Advanced Fiber Materials 2022年第1期4卷 5-23页

作者： Lu Wang fenghua zhang Yanju Liu Jinsong Leng Centre for Composite Materials and Structures Harbin Institute of Technology(HIT)No.2 Yikuang StreetHarbin 150080People’s Republic of China Department of Astronautic Science and Mechanics Harbin Institute of Technology(HIT)No.92 West Dazhi StreetHarbin 150001People’s Republic of China

Shape memory polymer(SMP)is a kind of material that can sense and respond to the changes of the external environment,and its behavior is similar to the intelligent refection of ***,as a versatile and feasible technique,has been used to prepare shape memory polymer fbers(SMPFs)and expand their *** show some advanced features and functions in many *** this review,we give a comprehensive overview of SMPFs,including materials,fabrication methods,structures,multifunction,and ***,the mechanism and characteristics of SMP are *** then discuss the electrospinning method to form various microstructures,like non-woven fbers,core/shell fbers,hollow fbers and oriented ***,the multiple functions of SMPFs are discussed,such as multi-shape memory efect,reversible shape memory efect and remote actuation of *** also focus on some typical applications of SMPFs,including biomedical scafolds,drug carriers,self-healing,smart textiles and sensors,as well as energy harvesting *** the end,the challenges and future development directions of SMPFs are proposed.

关键词： Shape memory polymer Micro/nano fbers Electrospinning Microstructures Multifunctional composites Applications

Shape Memory Polymer Composites:4D Printing,Smart Structures,and Applications

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Research 2024年第3期2023卷 319-343页

作者： Shiyu Yan fenghua zhang Lan Luo Linlin Wang Yanju Liu Jinsong Leng Centre for Composite Materials and Structures Harbin Institute of Technology(HIT)No.2 Yikuang StreetHarbin 150000People's Republic of China Department of Astronautic Science and Mechanics Harbin Institute of Technology(HIT)No.92 West Dazhi StreetHarbin 150000People's Republic of China.

Shape memory polymers (SMPs) and their composites (SMPCs) are smart materials that can be stably deformed and then return to their original shape under external stimulation, thus having a memory of their shape. Three-dimensional (3D) printing is an advanced technology for fabricating products using a digital software tool. Four-dimensional (4D) printing is a new generation of additive manufacturing technology that combines shape memory materials and 3D printing technology. Currently, 4D-printed SMPs and SMPCs are gaining considerable research attention and are finding use in various fields, including biomedical science. This review introduces SMPs, SMPCs, and 4D printing technologies, highlighting several special 4D-printed structures. It summarizes the recent research progress of 4D-printed SMPs and SMPCs in various fields, with particular emphasis on biomedical applications. Additionally, it presents an overview of the challenges and development prospects of 4D-printed SMPs and SMPCs and provides a preliminary discussion and useful reference for the research and application of 4D-printed SMPs and SMPCs.

关键词： composites printing Smart

Progress of passive daytime radiative cooling technologies towards commercial applications

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Particuology 2022年第8期20卷 57-67页

作者： Yan Cui Xianyu Luo fenghua zhang Le Sun Nuo Jjin Weimin Yang College of Mchanical and Eectrical Engineeing Beijing University of Chemical Techology Bejing 100029 China

Global warming has become one of the major environmental problems facing mankind in the 21st century,The existing refrigeration technology of buildings,like air conditioning,consumes a lot of *** daytime radiative cooling technology works without consuming *** emitting carbon dioxide and other greenhouse *** review summarizes the development of daytime passive radiative cooling technologyfrom the basic principles,structure and materials of radiative coolers;analyses and evaluates the various existing radiative *** core of radiative cooling lies in the combination of multi-scale micro/nano *** cooler reflects sunlight thus preventing the building from being heated up;while allows the building toradiate its own heat out thus being cooled down;meanwhile maintains the temperature difference by the heat insulation effect ofthe porous structure in *** common challenges and potential solutions for the commercialization of radiative cooling technologies are analyzed,which may promote the applications of the technology in the near future.

关键词： Passive daytime radiative cooling Micro/nano particles Porous structure Micro/nano structures

Soil aggregation and aggregate-associated organic carbon under typical natural halophyte communities in arid saline areas of Northwest China

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Pedosphere 2020年第2期30卷 236-243页

作者： Zhibo CHENG Jingya WANG William JGALE Haichang YANG fenghua zhang College of Agronomy Shihezi UniversityXinjiang 832003China Key Laboratory of Oasis Ecology Agriculture of Xinjiang Shihezi UniversityXinjiang 832003China

Information on the effects of halophyte communities on soil organic carbon(SOC)is useful for sequestrating C in arid *** this study,we identified four typical natural halophyte communities in the Manasi River Basin in Xinjiang Province,Northeast China,namely,Karelinia caspia(Pall.)Less.,Bassia dasyphylla(*** ***.)Kuntze,Haloxylon ammodendron(***.)Bunge,and Tamarix ramosissima *** compared soil aggregation and aggregated-associated SOC under these *** aggregate fraction of 0.053–0.25 mm accounted for 47%–75%of the total soil mass,significantly more than the>0.25 and0.25 mm aggregates(13.3%–43.8%)and *** community having more0.25 mm fraction,followed by the***(4.9 g kg^-1)>***(4.2 g kg^-1)>***(3.4 g kg^-1).The *** community had the highest total SOC and aggregate-associated SOC,which was primarily because aggregate-associated SOC content at the 0–10 and 10–20 cm depths under this community were higher than those under other plant *** *** community could be beneficial for increasing SOC in saline soils in the arid region.

关键词： arid regions C sequestration soil aggregates soil organic C saline soils

Design of 4D printed shape-changing tracheal stent and remote controlling actuation

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International Journal of Smart and Nano Materials 2021年第4期12卷 375-389页

作者： fenghua zhang Nan Wen Linlin Wang Yunqi Bai Jinsong Leng Centre for Composite Materials and Structures Harbin Institute of Technology(Hit)HarbinPeople’s Republic of China College of Chemistry Chemical Engineering and Resource UtilizationNortheast Forestry UniversityHarbinPeople’s Republic China College of Environment and Chemical Engineering Heilongjiang University of Science and TechnologyHarbinPeople’s Republic China

has a good application *** biodegradable stent can effectively reduce the damage to patients and improve the therapeutic performance of *** this work,a series of shape memory polylactic acid(Fe_(3)O_(4))composite tracheal stents were manufactured by 4D *** composite tracheal stents with different structures were ***,with the addition of magnetic particles Fe3 O4,the shape memory PLA/Fe_(3)O_(4)composite tracheal stent has a magnetic driving *** the magnetic field,the shape recovery process is completed within 40 s,and the shape recovery rate is more than 99%.Moreover,the 4D printed tracheal stent was also triggered by the irradiation of infrared lamp to realize the remote controlling *** research on the structure design and driving method of 4D printing tracheal stent expands the application scope of shape memory polymer composites in biomedical field,provides a new way for personalized implantable medical devices and minimally invasive *** is of great significance for better precision medical treatment.

关键词： Shape memory polymer composite 4D printing shape-changing tracheal stent magnetic field actuation infrared light actuation

A critical role of foxp3a-positive regulatory T cells in maintaining immune homeostasis in zebrafish testis development

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Journal of Genetics and Genomics 2020年第9期47卷 547-561页

作者： Xianmei Li fenghua zhang Nan Wu Ding Ye Yaqing Wang Xiaofan zhang Yonghua Sun Yong-An zhang State Key Laboratory of Freshwater Ecology and Biotechnology Innovation Academy for Seed DesignInstitute of HydrobiologyChinese Academy of SciencesWuhan430072China University of Chinese Academy of Sciences Beijing100049China Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and TechnologyQingdao266071China State Key Laboratory of Agricultural Microbiology College of FisheriesHuazhong Agricultural UniversityWuhan430070China

Suppressive regulatory T cells(Treg cells)play a vital role in preventing autoimmunity and restraining excessive immune response to both self-and *** on humans and mice show that the Forkhead box p3(Foxp3)is a key regulatory gene for the development and function of Treg *** zebrafish,Treg cells have been identified by using foxp3a as a reliable ***,little is known about the function of foxp3a and Treg cells in gonadal development and sex ***,we show that foxp3a is essential for maintaining immune homeostasis in zebrafish testis *** found that foxp3a was specifically expressed in a subset of T cells in zebrafish testis,while knockout of foxp3a led to deficiency of foxp3a-positive Treg cells in the *** than 80%of foxp3a^(-/-)mutants developed as subfertile males,and the rest of the mutants developed as fertile females with decreased *** study revealed that foxp3a^(-/-)mutants had a delayed juvenile ovary-to-testis transition in definite males and sex reversal in about half of the definite females,which led to a dominance of later male *** to the absence of foxp3a-positive Treg cells in the differentiating testis of foxp3a^(-/-)mutants,abundant T cells and macrophages expand to disrupt an immunosuppressive milieu,resulting in defective development of germ cells and gonadal somatic cells and leading to development of infertile ***,our study reveals that foxp3a-positive Treg cells play an essential role in the orchestration of gonadal development and sex differentiation in zebrafish.

关键词： Foxp3a Treg cell Immune homeostasis Gonadal development Zebrafish