Acetabular cups,which are among themost important implants in total hip arthroplasty,are usually made from titanium alloys with high porosity and adequate mechanical properties.The current three-dimensional(3D)printin...Acetabular cups,which are among themost important implants in total hip arthroplasty,are usually made from titanium alloys with high porosity and adequate mechanical properties.The current three-dimensional(3D)printing approaches to fabricate customized acetabular cups have some inherent disadvantages such as high cost and energy consumption,residual thermal stress,and relatively low efficiency.Thus,in this work,a direct ink writing method was developed to print a cup structure at room temperature,followed by multi-step heat treatment to form microscale porous structure within the acetabular cup.Our method is facilitated by the development of a self-supporting titanium-6 aluminum-4 vanadium(Ti64)ink that is composed of Ti64 particles,bentonite yield-stress additive,ultraviolet curable polymer,and photo-initiator.The effects of Ti64 and bentonite concentrations on the rheological properties and printability of inks were systematically investigated.Moreover,the printing conditions,geometrical limitations,and maximum curing depth were explored.Finally,some complex 3D structures,including lattices with different gap distances,honeycomb with a well-defined shape,and an acetabular cup with uniformly distributed micropores,were successfully printed/fabricated to validate the effectiveness of the proposed method.展开更多
3D printing in the textile and fashion industry is a new emerging technology.Applications of 3D printing for designing clothes and other wearable accessories require tribological and biological understanding of 3D pri...3D printing in the textile and fashion industry is a new emerging technology.Applications of 3D printing for designing clothes and other wearable accessories require tribological and biological understanding of 3D printing plastics against the complex human skin to mitigate skin-friction related ailments such as calluses and blisters.This study provides tribological insight in search of an optimal 3D printable material that has minimal friction against the skin.Two low friction 3D printable materials,thermoplastic polyurethane(TPU)and polyamide(TPA)were chosen and tribological testing was carried out against a water responsive skin model.The skin model was synthesized using a gelatine based model made with cotton and crosslinked with glutaraldehyde.Tribological testing of TPU/TPA against the skin model in dry and wet conditions were made.The higher coefficient of friction(COF)was observed in the wet condition compared to the dry condition.To overcome the higher friction,TPA/TPU-sodium polyacrylate composites were prepared by heat pressing that significantly reduced COF of TPU and TPA by~40%and 75%,respectively,in wet conditions.展开更多
基金supported by the Micro Grant (PG20473) at the University of Nevada, Reno, USA
文摘Acetabular cups,which are among themost important implants in total hip arthroplasty,are usually made from titanium alloys with high porosity and adequate mechanical properties.The current three-dimensional(3D)printing approaches to fabricate customized acetabular cups have some inherent disadvantages such as high cost and energy consumption,residual thermal stress,and relatively low efficiency.Thus,in this work,a direct ink writing method was developed to print a cup structure at room temperature,followed by multi-step heat treatment to form microscale porous structure within the acetabular cup.Our method is facilitated by the development of a self-supporting titanium-6 aluminum-4 vanadium(Ti64)ink that is composed of Ti64 particles,bentonite yield-stress additive,ultraviolet curable polymer,and photo-initiator.The effects of Ti64 and bentonite concentrations on the rheological properties and printability of inks were systematically investigated.Moreover,the printing conditions,geometrical limitations,and maximum curing depth were explored.Finally,some complex 3D structures,including lattices with different gap distances,honeycomb with a well-defined shape,and an acetabular cup with uniformly distributed micropores,were successfully printed/fabricated to validate the effectiveness of the proposed method.
基金The authors acknowledge the financial support from US National Science Foundation(1852578)startup funding from the Department of Mechanical Engineering at the Uni vers让y of Nevada,Reno.
文摘3D printing in the textile and fashion industry is a new emerging technology.Applications of 3D printing for designing clothes and other wearable accessories require tribological and biological understanding of 3D printing plastics against the complex human skin to mitigate skin-friction related ailments such as calluses and blisters.This study provides tribological insight in search of an optimal 3D printable material that has minimal friction against the skin.Two low friction 3D printable materials,thermoplastic polyurethane(TPU)and polyamide(TPA)were chosen and tribological testing was carried out against a water responsive skin model.The skin model was synthesized using a gelatine based model made with cotton and crosslinked with glutaraldehyde.Tribological testing of TPU/TPA against the skin model in dry and wet conditions were made.The higher coefficient of friction(COF)was observed in the wet condition compared to the dry condition.To overcome the higher friction,TPA/TPU-sodium polyacrylate composites were prepared by heat pressing that significantly reduced COF of TPU and TPA by~40%and 75%,respectively,in wet conditions.
