Improvements in aero-engine performance have made the structures of the aero-engine components increasingly complex.To better adapt to the processing requirements of narrow twisted channels such as an integral shroude...Improvements in aero-engine performance have made the structures of the aero-engine components increasingly complex.To better adapt to the processing requirements of narrow twisted channels such as an integral shrouded blisk,this study proposes an innovative method of electrochemical cutting in which a flexible tube electrode is controlled by online deformation during processing.In this study,the processing principle of electrochemical cutting with a flexible electrode for controlled online deformation(FECC)was revealed for the first time.The online deformation process of flexible electrodes and the machining process of profiles were analysed in depth,and the corresponding theoretical models were established.Conventional electrochemical machining(ECM)is a multi-physical field-coupled process involving electric and flow fields.In FECC,classical mechanics are introduced into the tool cathode,which must be loaded at all times during the machining process.Therefore,in this study,before and after the deformation of the flexible electrode,a corresponding simulation study was conducted to understand the influence of the online deformation of the flexible electrode on the flow and electric fields.The feasibility of flexible electrodes for online deformation and the validity of the theoretical model were verified by deformation measurements and in situ observation experiments.Finally,the method was successfully applied to the machining of nickel-based high-temperature alloys,and different specifications of flexible electrodes were used to complete the machining of the corresponding complex profiles,thereby verifying the feasibility and versatility of the method.The method proposed in this study breaks the tradition of using a non-deformable cathode for ECM and adopts a flexible electrode that can be deformed during the machining process as the tool cathode,which improves machining flexibility and provides a valuable reference to promote the ECM of complex profiles.展开更多
To meet the demand for the machining of blisks with narrow cascade channels and twisted blade profiles,especially integral shrouded blisks with shrouds,this paper innovatively proposes a method for dynamic deformation...To meet the demand for the machining of blisks with narrow cascade channels and twisted blade profiles,especially integral shrouded blisks with shrouds,this paper innovatively proposes a method for dynamic deformation electrochemical cutting of flexible electrodes with arrayed group slit structure.By applying torque to both ends of the flexible electrode,the proposed method produces bending deformation and realizes the processing of a twisted profile.The flexible electrode is an important carrier of this method,and its properties such as elasticity,rigidity,and flow field uniformity have a crucial impact on smooth processing.Therefore,this paper proposes a design theory of flexible electrodes with an arrayed group slit structure and designs flexible electrodes with variable cross-sections.Compared with traditional uniform section tube electrode,the designed flexible electrode was subjected to the corresponding mechanical simulation,flow field simulation,and fluid–structure interaction simulation to investigate the elasticity,rigidity,and flow field uniformity of the flexible electrode.In addition,a deformation device of flexible electrodes was constructed and the corresponding experiments were carried out.Simulations and experiments demonstrate that flexible electrodes with arrayed group slit structures have good comprehensive performance.Finally,typical components were successfully machined to verify the feasibility of the proposed method and the rationality of the designed flexible electrode.It is shown that the proposed method has great potential for the machining of distorted profiles and provides a new idea for the machining of complex profiles.展开更多
Radiofrequency ablation(RFA)is a form of minimally invasive procedure that precisely ablates abnormal lesions or hyperplastic tissues through thermal energy generated by the radiofrequency current at the tip electrode...Radiofrequency ablation(RFA)is a form of minimally invasive procedure that precisely ablates abnormal lesions or hyperplastic tissues through thermal energy generated by the radiofrequency current at the tip electrode of the flexible catheter,which aims to partially or fully restore the function of the corresponding tissues or organs.Accurate prediction and control of thermal fields are crucial for clinical thermal ablation to ensure precise control of the ablation lesion size and prevent excessive burning of healthy tissues.In this study,an axisymmetric analytical model is developed for the electrothermal analysis of RFA in the cambered tissue surface and verified with the finite element analysis(FEA),which incorporates both the thermal field induced by the radiofrequency current and Pennes'biothermal effect.This model utilizes analytically derived electric and thermal fields to accurately predict the increase in the tissue temperature and the time-varying size of ablation lesion in the tissue.Furthermore,the parameters such as the input current density,curvature,and convective heat transfer coefficient of blood have a significant effect on the thermal field and thus the ablation lesion size.This electrothermal analytical model with a large curvature may provide a theoretical foundation and guidance for the future RFA applications on large-curvature biological surfaces,thereby enhancing accuracy,reducing the need for re-ablation,and lowering the costs associated with the design and production of ablation catheters.展开更多
With the spectacular rise of wearable and portable electronics,flexible power supplying systems with robust mechanical flexibility and high energy storage performance under various mechanical deformation conditions ar...With the spectacular rise of wearable and portable electronics,flexible power supplying systems with robust mechanical flexibility and high energy storage performance under various mechanical deformation conditions are imperative to be needed.Sodium ion batteries(SIBs)with sustainable natural abundance,low cost and superb properties similar to equivalent lithium ion batteries(LIBs),which have shown significant potentials as energy source for flexible electronic devices.In this review,the recent advances in flexible electrode materials based on different types of conductive substrates are addressed and the strategies underlying rational design for flexible structures are highlighted,as well as their applications in flexible SIBs.The remaining key challenges in rational electrodes design are discussed,and perspectives for practical applications of flexible SIBs are proposed as general guidance for future research of high-performance flexible SIBs.展开更多
Free organic solvent ink containing graphite, carboxymethyl cellulose and microfibrillated cellulose as active material, dispersing and binder, respectively, has been formulated to produce flexible and eco- sustainabl...Free organic solvent ink containing graphite, carboxymethyl cellulose and microfibrillated cellulose as active material, dispersing and binder, respectively, has been formulated to produce flexible and eco- sustainable electrodes for lithium ion batteries. Content ratio of components and dispersion protocol were tailored in order to have theological properties suitable for a large and cheap manufacturing process as well as screen printing. The bio-sourced printed electrodes exhibit a high porosity value of 70% that limits the electrochemical performances. However, the calendering process enhances electrode performances by increasing the reversible capacity from 85 until 315 mAh/g and reducing porosity to an optimal value of 34%. Moreover the introduction of 2% w/w of monofluoro-ethylene carbonate in the electrolyte reduced their reversible capacity loss of 11% in the printed electrode.展开更多
The recent rapid growth in electronics has reached the point where there is a need for solid-state devices with excellent physical flexibility, which will be a significant advantage in modern electronic devices. In ...The recent rapid growth in electronics has reached the point where there is a need for solid-state devices with excellent physical flexibility, which will be a significant advantage in modern electronic devices. In particular, metal nanowires and nano-particles are chosen for electrodes because of their low resistance and high mechanical stability. Among the various alternatives, Ag nanomaterials have recently garnered increasing attention due to the high intrinsic conductivity, a transparency with a low sheet resistance and relatively low cost. We herein summarize recent developments toward flexible electronics on the basis of Ag nanomaterials , which show promising performance and outperform the commonly used. The typical fabrication techniques along with the promising applications for flexible devices, are thoroughly discussed.展开更多
ZnO nanowires(ZnO NWs),ZnO nanoparticles(ZnO NPs)and carbon dots(C-dots)were synthesized by hydrothermal,sol-gel and hydrothermal methods respectively.They were also characterized and applied for dye sensitized solar ...ZnO nanowires(ZnO NWs),ZnO nanoparticles(ZnO NPs)and carbon dots(C-dots)were synthesized by hydrothermal,sol-gel and hydrothermal methods respectively.They were also characterized and applied for dye sensitized solar cells(DSSCs).The effects of C-dots on ZnO NWs and ZnO NPs have been evaluated.The C-dots were used at a mole ratio of citric acid(CA)to ethylene diamine(EDA)of 1:1.5.These C-dots were found to enhance the performance of the flexible electrode DSSCs.After the addition of C-dots,the power conversion efficiency(PCE)of ZnO NPs was boosted to be two times higher than that of ZnO NPs DSSCs without C-dots.Similarly,the ultraviolet(UV)-band revealed a blue shift,resulting in a lower band gap and a reduced charge transfer resistance,which can enhance the PCE of DSSCs.The loaded quantity on the flexible electrode substrate made of polyethylene terephthalate(PET)was optimized(50 mg).For DSSCs,the PET flexible electrode conductive polymer has produced positive outcomes.For ZnO NWs and ZnO NWs@C-dots,the PCE values were 1.45%and 4.25%;while for ZnO NPs and ZnO NPs@C-dots,they were 2.34%and 5.81%,respectively.This work achieved remarkable and competitive performance when compared to solid(indium tin oxides/glass)-based substrate.展开更多
Flexible electrodes have been widely focused on in recent years due to their special mechanical properties,which can be directly integrated onto human soft tissues to actively take effects on human body or passively m...Flexible electrodes have been widely focused on in recent years due to their special mechanical properties,which can be directly integrated onto human soft tissues to actively take effects on human body or passively monitor human vital signs.These flexible electrodes provide a new routine to realize clinical treatment of accurate thermal ablation in the biological tissues via radiofrequency ablation(RFA).Meanwhile,accurately controlling of thermal field is very significant for the thermal ablation in the clinical therapeutics to prevent the healthy tissue from excessive burning.In this paper,both one-dimensional and two-dimensional axisymmetric analytical models for the electrothermal analysis of radiofrequency ablation considering bio-heat transfer are established,which are verified by finite element analysis(FEA)and in vitro experiments on pig skins.In the model,the electrical field and thermal field are both derived analytically to accurately predict the temperature rise in the biological tissues.Furthermore,parameters,such as the blood flow convection in living tissues and thickness of tissue,have obvious effects on the thermal field in the tissues.They may pave the theoretical foundation and provide guidance of RFA with flexible electrodes in the future.展开更多
Neural representations arise from high-dimensional population activity,but current neuromodulation methods lack the precision to write information into the central nervous system at this complexity.In this perspective...Neural representations arise from high-dimensional population activity,but current neuromodulation methods lack the precision to write information into the central nervous system at this complexity.In this perspective,we propose high-dimensional stimulation as an approach to better approximate natural neural codes for brain-machine interfaces.Key advancements in resolution,coverage,and safety are essential,with flexible microelectrode arrays offering a promising path toward precise synthetic neural codes.展开更多
In pursuit of meeting the demands for the next generation of high energy density and flexible electronic products,there is a growing interest in flexible energy storage devices.Silicon(Si)stands out as a promising ele...In pursuit of meeting the demands for the next generation of high energy density and flexible electronic products,there is a growing interest in flexible energy storage devices.Silicon(Si)stands out as a promising electrode material due to its high theoretical specific capacity(~3579 mA h g^(-1)),low lithiation potential(~0.40 V),and abundance in nature.We have successfully developed freestanding and flexible CNT/Si/low-melting-point metal(LM)electrodes,which obviate the need for conductive additives,adhesives,and thereby increase the energy density of the device.As an anode material for lithium-ion batteries(LIBs),the CNT/Si/LM electrode demonstrates remarkable cycling stability and rate performance,achieving a reversible capacity of 1871.8 mA h g^(-1)after 100 cycles at a current density of 0.2 A g^(-1).In-situ XRD and in-situ thickness analysis are employed to elucidate the underlying mechanisms during the lithiation/delithiation.Density functional theory(DFT)calculations further substantiate the mechanism by which LM enhances the electrochemical performance of Si,focusing on the aspects of stress mitigation and reduction of the diffusion energy barrier.This research introduces a novel approach to flexible electrode design by integrating CNT films,LM,and Si,thereby charting a path forward for the development of next-generation flexible LIBs.展开更多
Flexible electronics is gaining prominence in modern technology,particularly in flexible displays,wearable electronics,and biomedical applications.Electrodes,as core components of flexible electronics,demand high cond...Flexible electronics is gaining prominence in modern technology,particularly in flexible displays,wearable electronics,and biomedical applications.Electrodes,as core components of flexible electronics,demand high conductivity,flexibility,and stretchability.However,traditional rigid conductive materials often generate interfacial slip with elastic substrates due to mismatched Young's modulus,adversely affecting device performance.Room-temperature liquid metals(LMs),with their high conductivity and stretchability,have emerged as ideal materials for stable and reliable flexible electronic devices.This review discusses the physical,chemical,and biocompatibility properties of LMs.Additionally,LM-based fabrication strategies including patterning and sintering for flexible electrodes are outlined.Applications in implantable medical devices,wearable electronics,and flexible energy storage are illustrated.Finally,the primary challenges and future research directions in LMs are identified.展开更多
Thick,flexible electrodes are essential to simultaneously achieving flexibility and high energy density;however,mechanical failure and the sluggish movement of ions and electrons both restrict their application.Here,a...Thick,flexible electrodes are essential to simultaneously achieving flexibility and high energy density;however,mechanical failure and the sluggish movement of ions and electrons both restrict their application.Here,a thick electrode reinforced by a stainless-steel(SS)fiber three-dimensional(3D)current collector is proposed that simultaneously attains unprecedented flexibility and a high energy density.This ultra-flexible electrode is prepared by a thermally induced phase separation process.Its meso/macroporosity enhances ionic conductivity,and the 3D fiber reinforcement enhances interfacial adhesion,flexural durability,and electrical conductivity.Owing to these advantages,the fiber-reinforced electrode has a minimum bending radius of 3 mm owing to its high yield strain(13%)and attains a high energy density of 500 Wh·L^(-1),which is considerably higher than that of previous flexible batteries(100–350 Wh·L^(-1)).In contrast with the same electrode coated on metal foil,which suffers from delamination,the fiber-reinforced electrode is delamination-free and outperforms in rate capability and cycling performance.Unlike conventional current collectors(foil,mesh,or foam),the SS fiber can be tailored to be distrib-uted throughout the electrode and to fit the electrode form factor.Fiber-reinforced electrodes are also excellent at creating 3D free-form batteries,which are difficult to fabricate with conventional electrode structures.展开更多
Flexible perovskite solar cells(FPSCs) have attracted enormous interest in wearable and portable electronics due to their high power-per-weight and low cost. Flexible and efficient perovskite solar cells require the d...Flexible perovskite solar cells(FPSCs) have attracted enormous interest in wearable and portable electronics due to their high power-per-weight and low cost. Flexible and efficient perovskite solar cells require the development of flexible electrodes compatible with the optoelectronic properties of perovskite. In this review, the recent progress of flexible electrodes used in FPSCs is comprehensively reviewed. The major features of flexible transparent electrodes, including transparent conductive oxides, conductive polymer, carbon nanomaterials and nanostructured metallic materials are systematically compared. And the corresponding modification strategies and device performance are summarized. Moreover, flexible opaque electrodes including metal films, opaque carbon materials and metal foils are critically assessed. Finally, the development directions and difficulties of flexible electrodes are given.展开更多
Nanostructured porous polyaniline(PANI)has been synthesized and coated simultaneously on a highly flexible and conductive carbon cloth(CC)substrate using a simple in-situ chemical oxidative polymerization technique.PA...Nanostructured porous polyaniline(PANI)has been synthesized and coated simultaneously on a highly flexible and conductive carbon cloth(CC)substrate using a simple in-situ chemical oxidative polymerization technique.PANI coated CC(PANI-CC)based flexible electrodes were further used for the fabrication of flexible supercapacitor devices.For the comparison purpose,pure PANI has also been synthesized and tested for its electrochemical performance.The energy storage capacity of PANI and PANI–CC composite was investigated using electrochemical techniques like CV,GCD,and EIS in a potential range from 0 to 0.8 V in 1 M H_(2)SO_(4)electrolyte.PANI-CC flexible electrodes exhibited the highest specific capacitance of 691 F/g;whereas,pure PANI could only achieve 575 F/g of specific capacitance at 1 A/g.Composite also exhibited outstanding cyclic stability by recollecting 94%of its initial capacitance after 2000 GCD cycles.For actual implementation,a flexible supercapacitor device has been fabricated using stainless steel sheets and PANI-CC flexile electrodes.The energy storage performance of the PANI-CC flexible supercapacitor device was tested at several bending angles,which resulted in 72%of capacitance retention at a maximum bending angle of 140°compared to the capacitance obtained at an angle 0°(flat state).PANI-CC exhibited improved electrochemical performance than pure PANI due to the synergistic effect between PANI and CC.Here,CC helped in enhancing the conductivity and stability;whereas,PANI boosted the capacitance owing to its excellent porosity and fast pseudocapacitive charge storage response.展开更多
Flexible,lightweight and high conductivity substrates are required for the development of next-generation flexible Li-ion batteries(LIBs).In addition,the interfacial strength between the active material and flexible s...Flexible,lightweight and high conductivity substrates are required for the development of next-generation flexible Li-ion batteries(LIBs).In addition,the interfacial strength between the active material and flexible substrate should be optimized for high-performance LIBs.Herein,cotton cloth(CC)is employed as a flexible substrate,and electroless plating is utilized to deposit a layer of Cu nanoparticles,which enhances the conductivity of CC and acts as a precursor for the active material,i.e.,CuO.The results reveal that the in situ etching and subsequent heat treatment converted Cu film into CuO nanowires on CC substrate.Moreover,carbon nano tubes(CNTs)are introduced to enhance the connectivity of CuO nano wires.Consequently,the CuO/CNT/CC electrode rendered a high areal capacity of>700μAh-cm^(-2)after100 charge/discharge cycles as well as excellent rate capability.The current work presents a novel route to develop desirable substrates for next-generation flexible Li-ion batteries.展开更多
TiN, platinum （Pt） black and iridium oxide are introduced to the stimulating sites to improve the performance of the flexible electrode. Low temperature process is used to fabricate the modifying films. TiN is coate...TiN, platinum （Pt） black and iridium oxide are introduced to the stimulating sites to improve the performance of the flexible electrode. Low temperature process is used to fabricate the modifying films. TiN is coated on the gold sites by magnetron sputtering while platinum black and iridium oxide are coated by electroplating and electrodeposifion, respectively. The impedance of the electrode decreases dramatically after modification. The combined analysis of surface morphology and cyclic voltammograms （CV） in phosphate buffer saline （PBS） solution indicates that the modified electrode sites have larger electrode-electrolyte capacitance and smaller faradic resistance than unmodified sites, thus they have smaller electrochemical impedances.展开更多
Self-standing porous WP2 nanosheet arrays on carbon fiber cloth （WP2 NSs/CC） were synthesized and used as a 3D flexible hydrogen evolution electrode. Because of its 3D porous nanoarray structure, the WP2 NSs/CC exhi...Self-standing porous WP2 nanosheet arrays on carbon fiber cloth （WP2 NSs/CC） were synthesized and used as a 3D flexible hydrogen evolution electrode. Because of its 3D porous nanoarray structure, the WP2 NSs/CC exhibits a remarkable catalytic activity and a high stability. By using the experimental measurements and first-principle calculations, the underlying reasons for the excellent catalytic activity were further explored. Our work makes the present WPz NSs as a promising electrocatalyst for hydrogen evolution and provides a way to design and fabricate efficient hydrogen evolution electrodes through 3D porous nano-arrays architecture.展开更多
The advancement of energy storage technology has paved the way for the application of electrochemi-cal processes in achieving low-carbon and precise environmental pollution reduction.Electrodes play a crucial role in ...The advancement of energy storage technology has paved the way for the application of electrochemi-cal processes in achieving low-carbon and precise environmental pollution reduction.Electrodes play a crucial role in efficiently removing organic pollutants and heavy metals.To implement electrochemical pollution control technology in practical engineering,flexible electrode preparation is vital.This review highlights recent progress in flexible electrode research,focusing on the selection and structural design of flexible electrode materials.It summarizes the latest advancements in current collectors,active mate-rials,and preparation methods to enhance conductivity,flexibility,and cycle stability.The application of flexible electrodes in water pollution control is categorized into three aspects:Organic pollutants,inor-ganic pollutants,and composite pollutants.Finally,the challenges and research requirements for enhanc-ing electrode flexibility in environmental governance are discussed,along with prospects for their future applications.展开更多
Nanomaterials with various dimensionalities(e.g.,nanowires,nanofilms,two-dimensional materials,and three-dimensional nanostructures)have shown great potential in the recent development of flexible electronics.Conventi...Nanomaterials with various dimensionalities(e.g.,nanowires,nanofilms,two-dimensional materials,and three-dimensional nanostructures)have shown great potential in the recent development of flexible electronics.Conventionally,organic solvents are inevitable while integrating nanomaterials onto flexible substrates,where polymer mediator-assisted transfer techniques are involved.This often damages the flexible substrate and thus hamper the large-scale application of nanomaterials.Here we report a method using watersoluble sugar as a mediator to facilely transfer nanomaterials onto rigid or flexible substrates.This method requires no organic solvent during transfer.More importantly,the morphology and properties of transferred nanomaterials,such as shape,microstructure,resistivity,and transmittance are well preserved on the target substrate.We believe that this universal and rapid transfer method can greatly advance the applications of nanomaterials in the field of flexible devices and beyond.展开更多
For rechargeable aqueous zinc-ion batteries(ZIBs),the design of nanocomposites comprised of electrochemically active materials and carbon materials with novel structures has great prom-ise in addressing the issue of e...For rechargeable aqueous zinc-ion batteries(ZIBs),the design of nanocomposites comprised of electrochemically active materials and carbon materials with novel structures has great prom-ise in addressing the issue of electrical conductivity and structural stability in the electrode materials during electrochemical cycling.We report the production of a novel flexible electrode material,by anchoring MnO_(2) nanosheets on a B,N co-doped carbon nanotube ar-ray(BNCNTs)grown on carbon cloth(BNCNTs@MnO_(2)),which was fabricated by in-situ pyrolysis and hydrothermal growth.The generated BNCNTs were strongly bonded to the surface of the car-bon fibers in the carbon cloth which provides both excellent elec-tron transport and ion diffusion,and improves the stability and dur-ability of the cathode.Importantly,the BNCNTs offer more active sites for the hydrothermal growth of MnO_(2),ensuring a uniform dis-tribution.Electrochemical tests show that BNCNTs@MnO_(2) delivers a high specific capacity of 310.7 mAh g^(−1) at 0.1 A g^(−1),along with excellent rate capability and outstanding cycling stability,with a 79.7% capacity retention after 8000 cycles at 3 A g^(−1).展开更多
基金supported by the National Natural Science Foundation of China(52375443)the Innovative Research Group Project of the National Natural Science Foundation of China(51921003).
文摘Improvements in aero-engine performance have made the structures of the aero-engine components increasingly complex.To better adapt to the processing requirements of narrow twisted channels such as an integral shrouded blisk,this study proposes an innovative method of electrochemical cutting in which a flexible tube electrode is controlled by online deformation during processing.In this study,the processing principle of electrochemical cutting with a flexible electrode for controlled online deformation(FECC)was revealed for the first time.The online deformation process of flexible electrodes and the machining process of profiles were analysed in depth,and the corresponding theoretical models were established.Conventional electrochemical machining(ECM)is a multi-physical field-coupled process involving electric and flow fields.In FECC,classical mechanics are introduced into the tool cathode,which must be loaded at all times during the machining process.Therefore,in this study,before and after the deformation of the flexible electrode,a corresponding simulation study was conducted to understand the influence of the online deformation of the flexible electrode on the flow and electric fields.The feasibility of flexible electrodes for online deformation and the validity of the theoretical model were verified by deformation measurements and in situ observation experiments.Finally,the method was successfully applied to the machining of nickel-based high-temperature alloys,and different specifications of flexible electrodes were used to complete the machining of the corresponding complex profiles,thereby verifying the feasibility and versatility of the method.The method proposed in this study breaks the tradition of using a non-deformable cathode for ECM and adopts a flexible electrode that can be deformed during the machining process as the tool cathode,which improves machining flexibility and provides a valuable reference to promote the ECM of complex profiles.
基金supported by the National Natural Science Foundation of China(No.52375443)the Innovative Research Group Project of the National Natural Science Foundation of China(No.51921003)。
文摘To meet the demand for the machining of blisks with narrow cascade channels and twisted blade profiles,especially integral shrouded blisks with shrouds,this paper innovatively proposes a method for dynamic deformation electrochemical cutting of flexible electrodes with arrayed group slit structure.By applying torque to both ends of the flexible electrode,the proposed method produces bending deformation and realizes the processing of a twisted profile.The flexible electrode is an important carrier of this method,and its properties such as elasticity,rigidity,and flow field uniformity have a crucial impact on smooth processing.Therefore,this paper proposes a design theory of flexible electrodes with an arrayed group slit structure and designs flexible electrodes with variable cross-sections.Compared with traditional uniform section tube electrode,the designed flexible electrode was subjected to the corresponding mechanical simulation,flow field simulation,and fluid–structure interaction simulation to investigate the elasticity,rigidity,and flow field uniformity of the flexible electrode.In addition,a deformation device of flexible electrodes was constructed and the corresponding experiments were carried out.Simulations and experiments demonstrate that flexible electrodes with arrayed group slit structures have good comprehensive performance.Finally,typical components were successfully machined to verify the feasibility of the proposed method and the rationality of the designed flexible electrode.It is shown that the proposed method has great potential for the machining of distorted profiles and provides a new idea for the machining of complex profiles.
基金Project supported by the National Natural Science Foundation of China(Nos.U23A20111 and 12372160)。
文摘Radiofrequency ablation(RFA)is a form of minimally invasive procedure that precisely ablates abnormal lesions or hyperplastic tissues through thermal energy generated by the radiofrequency current at the tip electrode of the flexible catheter,which aims to partially or fully restore the function of the corresponding tissues or organs.Accurate prediction and control of thermal fields are crucial for clinical thermal ablation to ensure precise control of the ablation lesion size and prevent excessive burning of healthy tissues.In this study,an axisymmetric analytical model is developed for the electrothermal analysis of RFA in the cambered tissue surface and verified with the finite element analysis(FEA),which incorporates both the thermal field induced by the radiofrequency current and Pennes'biothermal effect.This model utilizes analytically derived electric and thermal fields to accurately predict the increase in the tissue temperature and the time-varying size of ablation lesion in the tissue.Furthermore,the parameters such as the input current density,curvature,and convective heat transfer coefficient of blood have a significant effect on the thermal field and thus the ablation lesion size.This electrothermal analytical model with a large curvature may provide a theoretical foundation and guidance for the future RFA applications on large-curvature biological surfaces,thereby enhancing accuracy,reducing the need for re-ablation,and lowering the costs associated with the design and production of ablation catheters.
基金financially supported by the National Natural Science Foundation of China(52101267)the China Postdoctoral Science Foundation(2021M690117)。
文摘With the spectacular rise of wearable and portable electronics,flexible power supplying systems with robust mechanical flexibility and high energy storage performance under various mechanical deformation conditions are imperative to be needed.Sodium ion batteries(SIBs)with sustainable natural abundance,low cost and superb properties similar to equivalent lithium ion batteries(LIBs),which have shown significant potentials as energy source for flexible electronic devices.In this review,the recent advances in flexible electrode materials based on different types of conductive substrates are addressed and the strategies underlying rational design for flexible structures are highlighted,as well as their applications in flexible SIBs.The remaining key challenges in rational electrodes design are discussed,and perspectives for practical applications of flexible SIBs are proposed as general guidance for future research of high-performance flexible SIBs.
基金partially supported by theénergies du Futur Carnot Institute(Investissements d’Avenir-grant agreement No.ANR-11-CARN-030-01)the facilities of the Tek Li Cell platform funded by the Région Rhone-Alpes(ERDF:European Regional Development Fund)
文摘Free organic solvent ink containing graphite, carboxymethyl cellulose and microfibrillated cellulose as active material, dispersing and binder, respectively, has been formulated to produce flexible and eco- sustainable electrodes for lithium ion batteries. Content ratio of components and dispersion protocol were tailored in order to have theological properties suitable for a large and cheap manufacturing process as well as screen printing. The bio-sourced printed electrodes exhibit a high porosity value of 70% that limits the electrochemical performances. However, the calendering process enhances electrode performances by increasing the reversible capacity from 85 until 315 mAh/g and reducing porosity to an optimal value of 34%. Moreover the introduction of 2% w/w of monofluoro-ethylene carbonate in the electrolyte reduced their reversible capacity loss of 11% in the printed electrode.
基金Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi,100 Persons Program of Shanxithe Project Supported by Science Foundation of North University of China(No.110248-28140)The Project Supported by Science and Technology on Electronic Test & Measurement Laboratory(No.110103112113)
文摘The recent rapid growth in electronics has reached the point where there is a need for solid-state devices with excellent physical flexibility, which will be a significant advantage in modern electronic devices. In particular, metal nanowires and nano-particles are chosen for electrodes because of their low resistance and high mechanical stability. Among the various alternatives, Ag nanomaterials have recently garnered increasing attention due to the high intrinsic conductivity, a transparency with a low sheet resistance and relatively low cost. We herein summarize recent developments toward flexible electronics on the basis of Ag nanomaterials , which show promising performance and outperform the commonly used. The typical fabrication techniques along with the promising applications for flexible devices, are thoroughly discussed.
文摘ZnO nanowires(ZnO NWs),ZnO nanoparticles(ZnO NPs)and carbon dots(C-dots)were synthesized by hydrothermal,sol-gel and hydrothermal methods respectively.They were also characterized and applied for dye sensitized solar cells(DSSCs).The effects of C-dots on ZnO NWs and ZnO NPs have been evaluated.The C-dots were used at a mole ratio of citric acid(CA)to ethylene diamine(EDA)of 1:1.5.These C-dots were found to enhance the performance of the flexible electrode DSSCs.After the addition of C-dots,the power conversion efficiency(PCE)of ZnO NPs was boosted to be two times higher than that of ZnO NPs DSSCs without C-dots.Similarly,the ultraviolet(UV)-band revealed a blue shift,resulting in a lower band gap and a reduced charge transfer resistance,which can enhance the PCE of DSSCs.The loaded quantity on the flexible electrode substrate made of polyethylene terephthalate(PET)was optimized(50 mg).For DSSCs,the PET flexible electrode conductive polymer has produced positive outcomes.For ZnO NWs and ZnO NWs@C-dots,the PCE values were 1.45%and 4.25%;while for ZnO NPs and ZnO NPs@C-dots,they were 2.34%and 5.81%,respectively.This work achieved remarkable and competitive performance when compared to solid(indium tin oxides/glass)-based substrate.
基金The authors acknowledge the supports from the National Natural Science Foundation of China(No.11772030)the Aeronautical Science Foundation of China(No.2018ZC51030).
文摘Flexible electrodes have been widely focused on in recent years due to their special mechanical properties,which can be directly integrated onto human soft tissues to actively take effects on human body or passively monitor human vital signs.These flexible electrodes provide a new routine to realize clinical treatment of accurate thermal ablation in the biological tissues via radiofrequency ablation(RFA).Meanwhile,accurately controlling of thermal field is very significant for the thermal ablation in the clinical therapeutics to prevent the healthy tissue from excessive burning.In this paper,both one-dimensional and two-dimensional axisymmetric analytical models for the electrothermal analysis of radiofrequency ablation considering bio-heat transfer are established,which are verified by finite element analysis(FEA)and in vitro experiments on pig skins.In the model,the electrical field and thermal field are both derived analytically to accurately predict the temperature rise in the biological tissues.Furthermore,parameters,such as the blood flow convection in living tissues and thickness of tissue,have obvious effects on the thermal field in the tissues.They may pave the theoretical foundation and provide guidance of RFA with flexible electrodes in the future.
基金funded by R01EY036094(L.L)R01NS102917(C.X)+1 种基金U01NS115588(C.X)U01NS131086(C.X&L.L.)。
文摘Neural representations arise from high-dimensional population activity,but current neuromodulation methods lack the precision to write information into the central nervous system at this complexity.In this perspective,we propose high-dimensional stimulation as an approach to better approximate natural neural codes for brain-machine interfaces.Key advancements in resolution,coverage,and safety are essential,with flexible microelectrode arrays offering a promising path toward precise synthetic neural codes.
基金the National Natural Science Foundation of China(22279070).
文摘In pursuit of meeting the demands for the next generation of high energy density and flexible electronic products,there is a growing interest in flexible energy storage devices.Silicon(Si)stands out as a promising electrode material due to its high theoretical specific capacity(~3579 mA h g^(-1)),low lithiation potential(~0.40 V),and abundance in nature.We have successfully developed freestanding and flexible CNT/Si/low-melting-point metal(LM)electrodes,which obviate the need for conductive additives,adhesives,and thereby increase the energy density of the device.As an anode material for lithium-ion batteries(LIBs),the CNT/Si/LM electrode demonstrates remarkable cycling stability and rate performance,achieving a reversible capacity of 1871.8 mA h g^(-1)after 100 cycles at a current density of 0.2 A g^(-1).In-situ XRD and in-situ thickness analysis are employed to elucidate the underlying mechanisms during the lithiation/delithiation.Density functional theory(DFT)calculations further substantiate the mechanism by which LM enhances the electrochemical performance of Si,focusing on the aspects of stress mitigation and reduction of the diffusion energy barrier.This research introduces a novel approach to flexible electrode design by integrating CNT films,LM,and Si,thereby charting a path forward for the development of next-generation flexible LIBs.
基金supported by the National Key Research and Development Program of China(No.2021YFA1401100)the National Natural Science Foundation of China(Nos.61825403 and 61921005)
文摘Flexible electronics is gaining prominence in modern technology,particularly in flexible displays,wearable electronics,and biomedical applications.Electrodes,as core components of flexible electronics,demand high conductivity,flexibility,and stretchability.However,traditional rigid conductive materials often generate interfacial slip with elastic substrates due to mismatched Young's modulus,adversely affecting device performance.Room-temperature liquid metals(LMs),with their high conductivity and stretchability,have emerged as ideal materials for stable and reliable flexible electronic devices.This review discusses the physical,chemical,and biocompatibility properties of LMs.Additionally,LM-based fabrication strategies including patterning and sintering for flexible electrodes are outlined.Applications in implantable medical devices,wearable electronics,and flexible energy storage are illustrated.Finally,the primary challenges and future research directions in LMs are identified.
基金supported by the Basic Research Program funded by the Korea Institute of Machinery and Materials(grant number NK242C,NK249G)the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2021M3H4A1A02099352).
文摘Thick,flexible electrodes are essential to simultaneously achieving flexibility and high energy density;however,mechanical failure and the sluggish movement of ions and electrons both restrict their application.Here,a thick electrode reinforced by a stainless-steel(SS)fiber three-dimensional(3D)current collector is proposed that simultaneously attains unprecedented flexibility and a high energy density.This ultra-flexible electrode is prepared by a thermally induced phase separation process.Its meso/macroporosity enhances ionic conductivity,and the 3D fiber reinforcement enhances interfacial adhesion,flexural durability,and electrical conductivity.Owing to these advantages,the fiber-reinforced electrode has a minimum bending radius of 3 mm owing to its high yield strain(13%)and attains a high energy density of 500 Wh·L^(-1),which is considerably higher than that of previous flexible batteries(100–350 Wh·L^(-1)).In contrast with the same electrode coated on metal foil,which suffers from delamination,the fiber-reinforced electrode is delamination-free and outperforms in rate capability and cycling performance.Unlike conventional current collectors(foil,mesh,or foam),the SS fiber can be tailored to be distrib-uted throughout the electrode and to fit the electrode form factor.Fiber-reinforced electrodes are also excellent at creating 3D free-form batteries,which are difficult to fabricate with conventional electrode structures.
基金financially supported by the National Natural Science Foundation of China(52192610)the National Key Research and Development Program of China(Grant 2021YFA0715600)+1 种基金the Key Research and Development Program of Shaanxi Province(Grant 2020GY-310)the Fundamental Research Funds for the Central Universities and the Innovation Fund of Xidian University。
文摘Flexible perovskite solar cells(FPSCs) have attracted enormous interest in wearable and portable electronics due to their high power-per-weight and low cost. Flexible and efficient perovskite solar cells require the development of flexible electrodes compatible with the optoelectronic properties of perovskite. In this review, the recent progress of flexible electrodes used in FPSCs is comprehensively reviewed. The major features of flexible transparent electrodes, including transparent conductive oxides, conductive polymer, carbon nanomaterials and nanostructured metallic materials are systematically compared. And the corresponding modification strategies and device performance are summarized. Moreover, flexible opaque electrodes including metal films, opaque carbon materials and metal foils are critically assessed. Finally, the development directions and difficulties of flexible electrodes are given.
基金the research grant obtained from the Government of India,Under the DST-Nanomission program(No.SR/NM/NS-1110/2012)the DST-Inspire program(IFA12-PH-33)。
文摘Nanostructured porous polyaniline(PANI)has been synthesized and coated simultaneously on a highly flexible and conductive carbon cloth(CC)substrate using a simple in-situ chemical oxidative polymerization technique.PANI coated CC(PANI-CC)based flexible electrodes were further used for the fabrication of flexible supercapacitor devices.For the comparison purpose,pure PANI has also been synthesized and tested for its electrochemical performance.The energy storage capacity of PANI and PANI–CC composite was investigated using electrochemical techniques like CV,GCD,and EIS in a potential range from 0 to 0.8 V in 1 M H_(2)SO_(4)electrolyte.PANI-CC flexible electrodes exhibited the highest specific capacitance of 691 F/g;whereas,pure PANI could only achieve 575 F/g of specific capacitance at 1 A/g.Composite also exhibited outstanding cyclic stability by recollecting 94%of its initial capacitance after 2000 GCD cycles.For actual implementation,a flexible supercapacitor device has been fabricated using stainless steel sheets and PANI-CC flexile electrodes.The energy storage performance of the PANI-CC flexible supercapacitor device was tested at several bending angles,which resulted in 72%of capacitance retention at a maximum bending angle of 140°compared to the capacitance obtained at an angle 0°(flat state).PANI-CC exhibited improved electrochemical performance than pure PANI due to the synergistic effect between PANI and CC.Here,CC helped in enhancing the conductivity and stability;whereas,PANI boosted the capacitance owing to its excellent porosity and fast pseudocapacitive charge storage response.
基金the National Natural Science Foundation of China(Nos.21701022 and51690161)the Fundamental Research Funds for the Central Universities(Nos.N182505037 and N182410001)+2 种基金the Young Elite Scientists Sponsorship Program by CAST(No.2018QNRC001)the Liao Ning Revitalization Talents Program(No.XLYC1807214)the National Training Program of Innovation and Entrepreneurship for Undergraduates(No.201910145260)。
文摘Flexible,lightweight and high conductivity substrates are required for the development of next-generation flexible Li-ion batteries(LIBs).In addition,the interfacial strength between the active material and flexible substrate should be optimized for high-performance LIBs.Herein,cotton cloth(CC)is employed as a flexible substrate,and electroless plating is utilized to deposit a layer of Cu nanoparticles,which enhances the conductivity of CC and acts as a precursor for the active material,i.e.,CuO.The results reveal that the in situ etching and subsequent heat treatment converted Cu film into CuO nanowires on CC substrate.Moreover,carbon nano tubes(CNTs)are introduced to enhance the connectivity of CuO nano wires.Consequently,the CuO/CNT/CC electrode rendered a high areal capacity of>700μAh-cm^(-2)after100 charge/discharge cycles as well as excellent rate capability.The current work presents a novel route to develop desirable substrates for next-generation flexible Li-ion batteries.
基金supported by the Major National Scientific Research Plan (Grant Nos. 2011CB933203, 2011CB933102)National Natural Science Foundation of China (Grant Nos. 61036002, 60877035, 31070965)
文摘TiN, platinum （Pt） black and iridium oxide are introduced to the stimulating sites to improve the performance of the flexible electrode. Low temperature process is used to fabricate the modifying films. TiN is coated on the gold sites by magnetron sputtering while platinum black and iridium oxide are coated by electroplating and electrodeposifion, respectively. The impedance of the electrode decreases dramatically after modification. The combined analysis of surface morphology and cyclic voltammograms （CV） in phosphate buffer saline （PBS） solution indicates that the modified electrode sites have larger electrode-electrolyte capacitance and smaller faradic resistance than unmodified sites, thus they have smaller electrochemical impedances.
文摘Self-standing porous WP2 nanosheet arrays on carbon fiber cloth （WP2 NSs/CC） were synthesized and used as a 3D flexible hydrogen evolution electrode. Because of its 3D porous nanoarray structure, the WP2 NSs/CC exhibits a remarkable catalytic activity and a high stability. By using the experimental measurements and first-principle calculations, the underlying reasons for the excellent catalytic activity were further explored. Our work makes the present WPz NSs as a promising electrocatalyst for hydrogen evolution and provides a way to design and fabricate efficient hydrogen evolution electrodes through 3D porous nano-arrays architecture.
基金support by the National Natural Science Foundation of China(No.42107226)Intergovernmental International Cooperation on Scientific and Technological Innovation(No.2023YFE0122500)Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.ES202223).
文摘The advancement of energy storage technology has paved the way for the application of electrochemi-cal processes in achieving low-carbon and precise environmental pollution reduction.Electrodes play a crucial role in efficiently removing organic pollutants and heavy metals.To implement electrochemical pollution control technology in practical engineering,flexible electrode preparation is vital.This review highlights recent progress in flexible electrode research,focusing on the selection and structural design of flexible electrode materials.It summarizes the latest advancements in current collectors,active mate-rials,and preparation methods to enhance conductivity,flexibility,and cycle stability.The application of flexible electrodes in water pollution control is categorized into three aspects:Organic pollutants,inor-ganic pollutants,and composite pollutants.Finally,the challenges and research requirements for enhanc-ing electrode flexibility in environmental governance are discussed,along with prospects for their future applications.
基金financially supported by the funds of the“Science Technology and Innovation Committee of Shenzhen Municipality”(grant No.JCYJ20160613160524999 and JCYJ20170817111714314)“Guangdong Innovative and Entrepreneurial Research Team Program”under contract No.2016ZT06G587+1 种基金the National Natural Science Foundation of China(No.51771089 and U1613204)the Key-Area Research and Development Program of Guangdong Province(No.2019B010931001).
文摘Nanomaterials with various dimensionalities(e.g.,nanowires,nanofilms,two-dimensional materials,and three-dimensional nanostructures)have shown great potential in the recent development of flexible electronics.Conventionally,organic solvents are inevitable while integrating nanomaterials onto flexible substrates,where polymer mediator-assisted transfer techniques are involved.This often damages the flexible substrate and thus hamper the large-scale application of nanomaterials.Here we report a method using watersoluble sugar as a mediator to facilely transfer nanomaterials onto rigid or flexible substrates.This method requires no organic solvent during transfer.More importantly,the morphology and properties of transferred nanomaterials,such as shape,microstructure,resistivity,and transmittance are well preserved on the target substrate.We believe that this universal and rapid transfer method can greatly advance the applications of nanomaterials in the field of flexible devices and beyond.
基金financial support from projects funded by the National Natural Science Foundation of China(52172038,22179017)the National Key Research and Development Program of China(2022YFB4101600,2022YFB4101601)。
文摘For rechargeable aqueous zinc-ion batteries(ZIBs),the design of nanocomposites comprised of electrochemically active materials and carbon materials with novel structures has great prom-ise in addressing the issue of electrical conductivity and structural stability in the electrode materials during electrochemical cycling.We report the production of a novel flexible electrode material,by anchoring MnO_(2) nanosheets on a B,N co-doped carbon nanotube ar-ray(BNCNTs)grown on carbon cloth(BNCNTs@MnO_(2)),which was fabricated by in-situ pyrolysis and hydrothermal growth.The generated BNCNTs were strongly bonded to the surface of the car-bon fibers in the carbon cloth which provides both excellent elec-tron transport and ion diffusion,and improves the stability and dur-ability of the cathode.Importantly,the BNCNTs offer more active sites for the hydrothermal growth of MnO_(2),ensuring a uniform dis-tribution.Electrochemical tests show that BNCNTs@MnO_(2) delivers a high specific capacity of 310.7 mAh g^(−1) at 0.1 A g^(−1),along with excellent rate capability and outstanding cycling stability,with a 79.7% capacity retention after 8000 cycles at 3 A g^(−1).
