Highly anisotropic thermal conductive materials are of significance in thermal management applications. However,accurate determination of ultrathin composite thermal properties is a daunting task due to the tiny therm...Highly anisotropic thermal conductive materials are of significance in thermal management applications. However,accurate determination of ultrathin composite thermal properties is a daunting task due to the tiny thermal conductance,severely hindering the further exploration of novel efficient thermal management materials, especially for size-confined environments. In this work, by utilizing a hybrid measuring method, we demonstrate an accurate determination of thermal properties for montmorillonite/reduced graphene oxide(MMT/r GO) composite film with a thickness range from 0.2 μm to2 μm. The in-plane thermal conductivity measurement is realized by one-dimensional(1D) steady-state heat conduction approach while the cross-plane one is achieved via a modified 3ω method. As-measured thermal conductivity results are cross-checked with different methods and known materials, revealing the high measurement accuracy. A high anisotropic ratio of 60.5, independent of composite thickness, is observed in our measurements, further ensuring the negligible measurement error. Notably, our work develops an effective approach to the determination of ultrathin composite thermal conductivity, which may promote the development of ultrathin composites for potential thermal-related applications.展开更多
This paper reports the fabrication of regular large-area laser-induced periodic surface structures(LIPSSs)in indium tin oxide(ITO)films via femtosecond laser direct writing focused by a cylindrical lens.The regular LI...This paper reports the fabrication of regular large-area laser-induced periodic surface structures(LIPSSs)in indium tin oxide(ITO)films via femtosecond laser direct writing focused by a cylindrical lens.The regular LIPSSs exhibited good properties as nanowires,with a resistivity almost equal to that of the initial ITO film.By changing the laser fluence,the nanowire resistances could be tuned from 15 to 73 kΩ/mm with a consistency of±10%.Furthermore,the average transmittance of the ITO films with regular LIPSSs in the range of 1200-2000 nm was improved from 21%to 60%.The regular LIPSS is promising for transparent electrodes of nano-optoelectronic devices-particularly in the near-infrared band.展开更多
各向异性导电胶膜粘接结构是微电子封装中广泛应用连接形式.粘接结构在外载荷的作用下,粘接界面容易出现损伤与破坏从而使得结构失效.运用内聚力模型(cohesive zone model))用有限元方法模拟了各向异性导电胶膜粘接结构在剥离测试中的...各向异性导电胶膜粘接结构是微电子封装中广泛应用连接形式.粘接结构在外载荷的作用下,粘接界面容易出现损伤与破坏从而使得结构失效.运用内聚力模型(cohesive zone model))用有限元方法模拟了各向异性导电胶膜粘接结构在剥离测试中的粘接界面损伤与破坏的过程.通过与相应的试验数据比较,验证了内聚力模型对于导电胶膜粘接界面损伤破坏数值模拟的可行性.模拟计算分析了粘接界面损伤破坏与界面张开位移的关系,计算结果表明,粘接界面在剥离力的作用下,出现损伤后将很快达到破坏进而引起粘接界面的失效.展开更多
基金Project supported by the National Basic Research Program of China (Grant No. 2016YFA0200800)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant Nos. XDB30000000 and XDB07030100)+2 种基金the Sinopec Innovation Scheme (A-527)the National Key Research and Development Program of China (Grant No. 2021YFA0715700)the National Science Fund for Distinguished Young Scholars, China (Grant No. 52125302)。
文摘Highly anisotropic thermal conductive materials are of significance in thermal management applications. However,accurate determination of ultrathin composite thermal properties is a daunting task due to the tiny thermal conductance,severely hindering the further exploration of novel efficient thermal management materials, especially for size-confined environments. In this work, by utilizing a hybrid measuring method, we demonstrate an accurate determination of thermal properties for montmorillonite/reduced graphene oxide(MMT/r GO) composite film with a thickness range from 0.2 μm to2 μm. The in-plane thermal conductivity measurement is realized by one-dimensional(1D) steady-state heat conduction approach while the cross-plane one is achieved via a modified 3ω method. As-measured thermal conductivity results are cross-checked with different methods and known materials, revealing the high measurement accuracy. A high anisotropic ratio of 60.5, independent of composite thickness, is observed in our measurements, further ensuring the negligible measurement error. Notably, our work develops an effective approach to the determination of ultrathin composite thermal conductivity, which may promote the development of ultrathin composites for potential thermal-related applications.
基金We are grateful for financial supports from the Ministry of Science and Technology of China(Grant No.2021YFA1401100)National Natural Science Foundation of China(Grant Nos.12074123,11804227,91950112),and the Foundation of‘Manufacturing beyond limits’of Shanghai.
文摘This paper reports the fabrication of regular large-area laser-induced periodic surface structures(LIPSSs)in indium tin oxide(ITO)films via femtosecond laser direct writing focused by a cylindrical lens.The regular LIPSSs exhibited good properties as nanowires,with a resistivity almost equal to that of the initial ITO film.By changing the laser fluence,the nanowire resistances could be tuned from 15 to 73 kΩ/mm with a consistency of±10%.Furthermore,the average transmittance of the ITO films with regular LIPSSs in the range of 1200-2000 nm was improved from 21%to 60%.The regular LIPSS is promising for transparent electrodes of nano-optoelectronic devices-particularly in the near-infrared band.
文摘各向异性导电胶膜粘接结构是微电子封装中广泛应用连接形式.粘接结构在外载荷的作用下,粘接界面容易出现损伤与破坏从而使得结构失效.运用内聚力模型(cohesive zone model))用有限元方法模拟了各向异性导电胶膜粘接结构在剥离测试中的粘接界面损伤与破坏的过程.通过与相应的试验数据比较,验证了内聚力模型对于导电胶膜粘接界面损伤破坏数值模拟的可行性.模拟计算分析了粘接界面损伤破坏与界面张开位移的关系,计算结果表明,粘接界面在剥离力的作用下,出现损伤后将很快达到破坏进而引起粘接界面的失效.
