Tailoring thermal history during additive manufacturing(AM)offers a feasible approach to customise the microstructure and properties of materials without changing alloy compositions or post-heat treatment,which is gen...Tailoring thermal history during additive manufacturing(AM)offers a feasible approach to customise the microstructure and properties of materials without changing alloy compositions or post-heat treatment,which is generally overlooked as it is hard to achieve in commercial materials.Herein,a customised Fe-Ni-Ti-Al maraging steel with rapid precipitation kinetics offers the opportunity to leverage thermal history during AM for achieving large-range tunable strength-ductility combinations.The Fe-Ni-Ti-Al steel was processed by laser-directed energy deposition(LDED)with different deposition strategies to tailor the thermal history.As the phase transformation and in-situ formation of multi-scale secondary phases of the Fe-Ni-Ti-Al steel are sensitive to the thermal histories,the deposited steel achieved a large range of tuneable mechanical properties.Specifically,the interlayer paused deposited sample exhibits superior tensile strength(∼1.54 GPa)and moderate elongation(∼8.1%),which is attributed to the formation of unique hierarchical structures and the in-situ precipitation of high-densityη-Ni_(3)(Ti,Al)during LDED.In contrast,the substrate heating deposited sample has an excellent elongation of 19.3%together with a high tensile strength of 1.24 GPa.The achievable mechanical property range via tailoring thermal history in the LDED-built Fe-Ni-Ti-Al steel is significantly larger than most commercial materials.The findings highlight the material customisation along with AM’s unique thermal history to achieve versatile mechanical performances of deposited materials,which could inspire more property or function manipulations of materials by AM process control or innovation.展开更多
Today＇s manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for com...Today＇s manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for companies to achieve their objectives. Efforts to mass customisation should be made on two aspects： （1） To modularize products and make them as less differences as possible; （2） To design manufacturing resources and make them provide as many processes variations as possible. This paper reports our recent work on aspect （2）, i.e. how to design a reconfignrable manufacturing system （RMS） so that it can be competent to accomplish various processes optimally; Reconfignrable robot system （RRS） is taken as an example. RMS design involves architecture design and configuration design, and configuration design is further divided in design analysis and design synthesis. Axiomatic design theory （ADT） is applied to architecture design, the features and issues of RRS configuration design are discussed, automatic modelling method is developed for design analysis, and concurrent design methodology is presented for design synthesis.展开更多
Ankle arthrodesis is a common procedure that resolves many conditions of the foot and ankle; however, complications following this procedure are often reported and vary depending on the fixation technique. Various tec...Ankle arthrodesis is a common procedure that resolves many conditions of the foot and ankle; however, complications following this procedure are often reported and vary depending on the fixation technique. Various techniques have been described in the attempt to achieve ankle arthrodesis and there is much debate as to the efficiency of each one. This study aims to evaluate the efficiency of anterior plating in ankle arthrodesis using customised and Synthes Tomo Fix plates. We present the outcomes of 28 ankle arthrodeses between 2005 and 2012, specifically examining rate of union, patient-reported outcomes scores, and complications. All 28 patients achieved radiographic union at an average of 36 wk; the majority of patients(92.86%) at or before 16 wk, the exceptions being two patients with Charcot joints who were noted to have bony union at a three year review. Patient-reported outcomes scores significantly increased(P < 0.05). Complications included two delayed unions as previously mentioned, infection, and extended postoperative pain. With multiple points for fixation and coaxial screw entry points, the contoured customised plate offers added compression and provides a rigid fixation for arthrodesis stabilization.展开更多
This paper presents a fully customised integrated gate commutated thyristor(IGCT)gate driver monolithic integrated circuit(GDMIC),aiming to address the many shortcomings of traditional IGCT gate driver units composed ...This paper presents a fully customised integrated gate commutated thyristor(IGCT)gate driver monolithic integrated circuit(GDMIC),aiming to address the many shortcomings of traditional IGCT gate driver units composed of discrete components,such as the excessive number of components,low reliability,and complex development processes.The current-source driving characteristics of IGCTs pose significant technical challenges for developing fully customised integrated circuits(IC).The customised requirements of IGCT gate driver chips under various operating conditions are explored regarding functional module division,power sequencing,and chip parameter specifications.However,existing high-side(HS)driver methods exhibit limitations in functional monolithic integration and bipolar complementary metal-oxide-semiconductor compat-ibility.To address these challenges,a novel HS driving topology based on floating linear regulators is proposed.It can achieve synchronised control of multi-channel floating power transistors while supporting 100%duty cycle continuous conduction.The pro-posed GDMIC reduces the three independent HS power supplies to a single multiplexed topology,significantly decreasing circuit complexity.Experimental results validate the feasibility and performance of a 4-inch gate driver prototype based on IGCT current-source management IC,demonstrating significant advantages in reducing the number of components,enhancing device reliability,and simplifying development.The proposed GDMIC offers an innovative development path for future high-power IGCT drivers.展开更多
With changing customer attitudes toward consumption and function homogenization,product appearance designs have an increasing influence on the purchase decision.Customer characteristics and emotional factors play an i...With changing customer attitudes toward consumption and function homogenization,product appearance designs have an increasing influence on the purchase decision.Customer characteristics and emotional factors play an important role here.This study proposes a novel approach for modelling satisfaction and accomplishing a configuration that overcomes the limitations of conventional methods to precisely predict satisfaction,provide optimal product recommendations,and advise manufacturers on product appearance design.The newly proposed approach considers satisfaction,clusters customers through the Kansei perspective,and constructs a satisfaction model for each cluster.Additionally,the study employs data mining to understand the basic design principles and conflicted combinations that must be followed and avoided,respectively.The bidirectional association rules-constrained genetic algorithm is presented to limit configuration freedom,ensuring that results are in the range of control.Comparing prediction errors and recommended sample votes between the novel and conventional approaches revealed the presented approach’s efficiency and accuracy,thereby providing suggestions for manufacturers to make precise decisions on launching new product appearance designs through predicting customer emotional satisfaction.展开更多
3D printing has opened new horizons for the manufacturing industry in general, and 3D printers have become the tools for technological advancements. There is a huge divide between the pricing of industrial and desktop...3D printing has opened new horizons for the manufacturing industry in general, and 3D printers have become the tools for technological advancements. There is a huge divide between the pricing of industrial and desktop 3D printers with the former being on the expensive side capable of producing excellent quality products and latter being on the low-cost side with moderate quality results. However, there is a larger room for improvements and enhancements for the desktop systems as compared to the industrial ones. In this paper, a desktop 3D printer called Prusa Mendel i2 has been modified and integrated with an additional extruder so that the system can work with dual extruders and produce bespoke electronic circuits. The communication between the two extruders has been established by making use of the In-Chip Serial Program- ming port on the Arduino Uno controlling the printer. The biggest challenge is to control the flow of electric paint （to be dispensed by the new extruder） and CFD （Computa- tional Fluid Dynamics） analysis has been carried out to ascertain the optimal conditions for proper dispensing. The final product is a customised electronic circuit with the base of plastic （from the 3D printer＇s extruder） and electronic paint （from the additional extruder） properly dispensed to create a live circuit on a plastic platform. This low-cost enhancement to a desktop 3D printer can provide a new prospect to produce multiple material parts where the additional extruder can be filled with any material that can be properly dispensed from its nozzle.展开更多
Polyether-ether-ketone(PEEK)is believed to be the next-generation biomedical material for orthopaedic implants that may replace metal materials because of its good biocompatibility,appropriate mechanical properties an...Polyether-ether-ketone(PEEK)is believed to be the next-generation biomedical material for orthopaedic implants that may replace metal materials because of its good biocompatibility,appropriate mechanical properties and radiolucency.Currently,some PEEK implants have been used successfully for many years.However,there is no customised PEEK orthopaedic implant made by additive manufacturing licensed for the market,although clinical trials have been increasingly reported.In this review article,design criteria,including geometric matching,functional restoration,strength safety,early fixation,long-term stability and manufacturing capability,are summarised,focusing on the clinical requirements.An integrated framework of design and manufacturing processes to create customised PEEK implants is presented,and several typical clinical applications such as cranioplasty patches,rib prostheses,mandibular prostheses,scapula prostheses and femoral prostheses are described.The main technical challenge faced by PEEK orthopaedic implants lies in the poor bonding with bone and soft tissue due to its biological inertness,which may be solved by adding bioactive fillers and manufacturing porous architecture.The lack of technical standards is also one of the major factors preventing additive-manufactured customised PEEK orthopaedic implants from clinical translation,and it is good to see that the abundance of standards in the field of additive-manufactured medical devices is helping them enter the clinical market.展开更多
基金financially supported by the Career Development Fund(Grant No.C210112051)under the Agency for Science,Technology and Research(A*STAR)of Singapore2022 MTC Young Individual Research Grants(Grant No:M22K3c0097)under Singapore Research,Innovation and Enterprise(RIE)2025 Plan,led by C Tan。
文摘Tailoring thermal history during additive manufacturing(AM)offers a feasible approach to customise the microstructure and properties of materials without changing alloy compositions or post-heat treatment,which is generally overlooked as it is hard to achieve in commercial materials.Herein,a customised Fe-Ni-Ti-Al maraging steel with rapid precipitation kinetics offers the opportunity to leverage thermal history during AM for achieving large-range tunable strength-ductility combinations.The Fe-Ni-Ti-Al steel was processed by laser-directed energy deposition(LDED)with different deposition strategies to tailor the thermal history.As the phase transformation and in-situ formation of multi-scale secondary phases of the Fe-Ni-Ti-Al steel are sensitive to the thermal histories,the deposited steel achieved a large range of tuneable mechanical properties.Specifically,the interlayer paused deposited sample exhibits superior tensile strength(∼1.54 GPa)and moderate elongation(∼8.1%),which is attributed to the formation of unique hierarchical structures and the in-situ precipitation of high-densityη-Ni_(3)(Ti,Al)during LDED.In contrast,the substrate heating deposited sample has an excellent elongation of 19.3%together with a high tensile strength of 1.24 GPa.The achievable mechanical property range via tailoring thermal history in the LDED-built Fe-Ni-Ti-Al steel is significantly larger than most commercial materials.The findings highlight the material customisation along with AM’s unique thermal history to achieve versatile mechanical performances of deposited materials,which could inspire more property or function manipulations of materials by AM process control or innovation.
文摘Today＇s manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for companies to achieve their objectives. Efforts to mass customisation should be made on two aspects： （1） To modularize products and make them as less differences as possible; （2） To design manufacturing resources and make them provide as many processes variations as possible. This paper reports our recent work on aspect （2）, i.e. how to design a reconfignrable manufacturing system （RMS） so that it can be competent to accomplish various processes optimally; Reconfignrable robot system （RRS） is taken as an example. RMS design involves architecture design and configuration design, and configuration design is further divided in design analysis and design synthesis. Axiomatic design theory （ADT） is applied to architecture design, the features and issues of RRS configuration design are discussed, automatic modelling method is developed for design analysis, and concurrent design methodology is presented for design synthesis.
文摘Ankle arthrodesis is a common procedure that resolves many conditions of the foot and ankle; however, complications following this procedure are often reported and vary depending on the fixation technique. Various techniques have been described in the attempt to achieve ankle arthrodesis and there is much debate as to the efficiency of each one. This study aims to evaluate the efficiency of anterior plating in ankle arthrodesis using customised and Synthes Tomo Fix plates. We present the outcomes of 28 ankle arthrodeses between 2005 and 2012, specifically examining rate of union, patient-reported outcomes scores, and complications. All 28 patients achieved radiographic union at an average of 36 wk; the majority of patients(92.86%) at or before 16 wk, the exceptions being two patients with Charcot joints who were noted to have bony union at a three year review. Patient-reported outcomes scores significantly increased(P < 0.05). Complications included two delayed unions as previously mentioned, infection, and extended postoperative pain. With multiple points for fixation and coaxial screw entry points, the contoured customised plate offers added compression and provides a rigid fixation for arthrodesis stabilization.
基金National Key Research and Development Program of China,Grant/Award Number:2021YFB2401604The Integration Projects of National Natural Science Foundation of China-State Grid Joint Fund for Smart Grid,Grant/Award Number:U2166602National Natural Science Foundation of China,Grant/Award Number:52241701。
文摘This paper presents a fully customised integrated gate commutated thyristor(IGCT)gate driver monolithic integrated circuit(GDMIC),aiming to address the many shortcomings of traditional IGCT gate driver units composed of discrete components,such as the excessive number of components,low reliability,and complex development processes.The current-source driving characteristics of IGCTs pose significant technical challenges for developing fully customised integrated circuits(IC).The customised requirements of IGCT gate driver chips under various operating conditions are explored regarding functional module division,power sequencing,and chip parameter specifications.However,existing high-side(HS)driver methods exhibit limitations in functional monolithic integration and bipolar complementary metal-oxide-semiconductor compat-ibility.To address these challenges,a novel HS driving topology based on floating linear regulators is proposed.It can achieve synchronised control of multi-channel floating power transistors while supporting 100%duty cycle continuous conduction.The pro-posed GDMIC reduces the three independent HS power supplies to a single multiplexed topology,significantly decreasing circuit complexity.Experimental results validate the feasibility and performance of a 4-inch gate driver prototype based on IGCT current-source management IC,demonstrating significant advantages in reducing the number of components,enhancing device reliability,and simplifying development.The proposed GDMIC offers an innovative development path for future high-power IGCT drivers.
基金supported by the National Social Science Fund of China(Grant No.18BGL095)
文摘With changing customer attitudes toward consumption and function homogenization,product appearance designs have an increasing influence on the purchase decision.Customer characteristics and emotional factors play an important role here.This study proposes a novel approach for modelling satisfaction and accomplishing a configuration that overcomes the limitations of conventional methods to precisely predict satisfaction,provide optimal product recommendations,and advise manufacturers on product appearance design.The newly proposed approach considers satisfaction,clusters customers through the Kansei perspective,and constructs a satisfaction model for each cluster.Additionally,the study employs data mining to understand the basic design principles and conflicted combinations that must be followed and avoided,respectively.The bidirectional association rules-constrained genetic algorithm is presented to limit configuration freedom,ensuring that results are in the range of control.Comparing prediction errors and recommended sample votes between the novel and conventional approaches revealed the presented approach’s efficiency and accuracy,thereby providing suggestions for manufacturers to make precise decisions on launching new product appearance designs through predicting customer emotional satisfaction.
文摘3D printing has opened new horizons for the manufacturing industry in general, and 3D printers have become the tools for technological advancements. There is a huge divide between the pricing of industrial and desktop 3D printers with the former being on the expensive side capable of producing excellent quality products and latter being on the low-cost side with moderate quality results. However, there is a larger room for improvements and enhancements for the desktop systems as compared to the industrial ones. In this paper, a desktop 3D printer called Prusa Mendel i2 has been modified and integrated with an additional extruder so that the system can work with dual extruders and produce bespoke electronic circuits. The communication between the two extruders has been established by making use of the In-Chip Serial Program- ming port on the Arduino Uno controlling the printer. The biggest challenge is to control the flow of electric paint （to be dispensed by the new extruder） and CFD （Computa- tional Fluid Dynamics） analysis has been carried out to ascertain the optimal conditions for proper dispensing. The final product is a customised electronic circuit with the base of plastic （from the 3D printer＇s extruder） and electronic paint （from the additional extruder） properly dispensed to create a live circuit on a plastic platform. This low-cost enhancement to a desktop 3D printer can provide a new prospect to produce multiple material parts where the additional extruder can be filled with any material that can be properly dispensed from its nozzle.
基金The work was supported by the National Key R&D Program of China(No.2018YFE0207900)the National Natural Science Foundation of China(No.51835010)+6 种基金the Key R&D Program of Guangdong Province,China(No.2018B090906001)China Postdoctoral Science Foundation(No.2020M683458)the Natural Science Basic Research Program of ShaanXi Province,China(No.2022JQ-378)the Engineering and Physical Science Research Council(EPSRC)via DTP Case Programme(No.EP/T517793/1)the Fundamental Research Funds for the Central Universities(No.XZY012021007)the Laboratory Construction Project for Jihua Laboratory(No.X200031TM200),Open Project(No.BHJ17C019)the Youth Innovation Team of Shaanxi Universities.
文摘Polyether-ether-ketone(PEEK)is believed to be the next-generation biomedical material for orthopaedic implants that may replace metal materials because of its good biocompatibility,appropriate mechanical properties and radiolucency.Currently,some PEEK implants have been used successfully for many years.However,there is no customised PEEK orthopaedic implant made by additive manufacturing licensed for the market,although clinical trials have been increasingly reported.In this review article,design criteria,including geometric matching,functional restoration,strength safety,early fixation,long-term stability and manufacturing capability,are summarised,focusing on the clinical requirements.An integrated framework of design and manufacturing processes to create customised PEEK implants is presented,and several typical clinical applications such as cranioplasty patches,rib prostheses,mandibular prostheses,scapula prostheses and femoral prostheses are described.The main technical challenge faced by PEEK orthopaedic implants lies in the poor bonding with bone and soft tissue due to its biological inertness,which may be solved by adding bioactive fillers and manufacturing porous architecture.The lack of technical standards is also one of the major factors preventing additive-manufactured customised PEEK orthopaedic implants from clinical translation,and it is good to see that the abundance of standards in the field of additive-manufactured medical devices is helping them enter the clinical market.
