Better electrical insulation and thermal management are both urgently required in integrated power semiconductors.Electrical insulation epoxy encapsulation suffers from poor heat conduction,which has increasingly beco...Better electrical insulation and thermal management are both urgently required in integrated power semiconductors.Electrical insulation epoxy encapsulation suffers from poor heat conduction,which has increasingly become a bottleneck of power semiconductors integration.Although incorporating high thermal conductivity ceramics,such as hexagonal boron nitride(hBN),aluminium nitride etc.into epoxy promotes the thermal conductivity,the eco-friendly scalable fabrication of these composites with sufficient electrical breakdown strength remains a formidable challenge.Suitable voltage stabilizers are known to provide additional benefits to breakdown strength.Herein,a highthroughput approach combining plasma with roll-to-roll was developed.The voltage stabilizer(acetophenone)was grafted on interfaces between hBN and epoxy matrix through plasma.The high-energy electrons are consumed by the grafted interface,which leads to the significant suppression of partial discharge in Epoxy/hBN.Meanwhile,interfacial phonon scattering is repaired by grafting.Therefore,the epoxy composite concurrently exhibits improved breakdown strength(by 27.4%)and thermal conductivity(by 142.9%)at about 11.9 wt.%filler content,outperforming the pure epoxy.Consequently,a promising modification strategy for mass production is provided for the encapsulation materials in various high-power-density semiconductor devices.展开更多
In bone tissue engineering,scaffolds with excellent mechanical and bioactive properties play prominent roles in space maintaining and bone regeneration,attracting increasingly interests in clinical practice.In this st...In bone tissue engineering,scaffolds with excellent mechanical and bioactive properties play prominent roles in space maintaining and bone regeneration,attracting increasingly interests in clinical practice.In this study,strontium-incorporatedβ-tricalcium phosphate(β-TCP),named Sr-TCP,bioceramic triply periodic minimal surface(TPMS)structured scaffolds were successfully fabricated by digital light processing(DLP)-based 3D printing technique,achieving high porosity,enhanced strength,and excellent bioactivity.The Sr-TCP scaffolds were first characterized by element distribution,macrostructure and microstructure,and mechanical properties.Notably,the compressive strength of the scaffolds reached 1.44 MPa with porosity of 80%,bringing a great mechanical breakthrough to porous scaffolds.Furthermore,the Sr-TCP scaffolds also facilitated osteogenic differentiation of mouse osteoblastic cell line(MC3T3-E1)cells in both gene and protein aspects,verified by alkaline phosphatase(ALP)activity and polymerase chain reaction(PCR)assays.Overall,the 3D-printed Sr-TCP bioceramic TPMS structured scaffolds obtained high porosity,boosted strength,and superior bioactivity at the same time,serving as a promising approach for bone regeneration.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:52277135Fund of the Key Laboratory of High Power Microwave Technology,Grant/Award Number:6142605190105Graduate Research and Innovation Foundation of Chongqing,Grant/Award Number:CYB22016。
文摘Better electrical insulation and thermal management are both urgently required in integrated power semiconductors.Electrical insulation epoxy encapsulation suffers from poor heat conduction,which has increasingly become a bottleneck of power semiconductors integration.Although incorporating high thermal conductivity ceramics,such as hexagonal boron nitride(hBN),aluminium nitride etc.into epoxy promotes the thermal conductivity,the eco-friendly scalable fabrication of these composites with sufficient electrical breakdown strength remains a formidable challenge.Suitable voltage stabilizers are known to provide additional benefits to breakdown strength.Herein,a highthroughput approach combining plasma with roll-to-roll was developed.The voltage stabilizer(acetophenone)was grafted on interfaces between hBN and epoxy matrix through plasma.The high-energy electrons are consumed by the grafted interface,which leads to the significant suppression of partial discharge in Epoxy/hBN.Meanwhile,interfacial phonon scattering is repaired by grafting.Therefore,the epoxy composite concurrently exhibits improved breakdown strength(by 27.4%)and thermal conductivity(by 142.9%)at about 11.9 wt.%filler content,outperforming the pure epoxy.Consequently,a promising modification strategy for mass production is provided for the encapsulation materials in various high-power-density semiconductor devices.
基金supported by the National Natural Science Foundation of China(Nos.51972339 and 51802350).
文摘In bone tissue engineering,scaffolds with excellent mechanical and bioactive properties play prominent roles in space maintaining and bone regeneration,attracting increasingly interests in clinical practice.In this study,strontium-incorporatedβ-tricalcium phosphate(β-TCP),named Sr-TCP,bioceramic triply periodic minimal surface(TPMS)structured scaffolds were successfully fabricated by digital light processing(DLP)-based 3D printing technique,achieving high porosity,enhanced strength,and excellent bioactivity.The Sr-TCP scaffolds were first characterized by element distribution,macrostructure and microstructure,and mechanical properties.Notably,the compressive strength of the scaffolds reached 1.44 MPa with porosity of 80%,bringing a great mechanical breakthrough to porous scaffolds.Furthermore,the Sr-TCP scaffolds also facilitated osteogenic differentiation of mouse osteoblastic cell line(MC3T3-E1)cells in both gene and protein aspects,verified by alkaline phosphatase(ALP)activity and polymerase chain reaction(PCR)assays.Overall,the 3D-printed Sr-TCP bioceramic TPMS structured scaffolds obtained high porosity,boosted strength,and superior bioactivity at the same time,serving as a promising approach for bone regeneration.
