| 1. |
- Fu, Yifeng, 1984, et al.
(författare)
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A complete carbon-nanotube-based on-chip cooling solution with very high heat dissipation capacity
- 2012
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Ingår i: Nanotechnology. - : IOP Publishing. - 1361-6528 .- 0957-4484. ; 23:4
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Tidskriftsartikel (refereegranskat)abstract
- Heat dissipation is one of the factors limiting the continuous miniaturization of electronics. In the study presented in this paper, we designed an ultra-thin heat sink using carbon nanotubes (CNTs) as micro cooling fins attached directly onto a chip. A metal-enhanced CNT transfer technique was utilized to improve the interface between the CNTs and the chip surface by minimizing the thermal contact resistance and promoting the mechanical strength of the microfins. In order to optimize the geometrical design of the CNT microfin structure, multi-scale modeling was performed. A molecular dynamics simulation (MDS) was carried out to investigate the interaction between water and CNTs at the nanoscale and a finite element method (FEM) modeling was executed to analyze the fluid field and temperature distribution at the macroscale. Experimental results show that water is much more efficient than air as a cooling medium due to its three orders-of-magnitude higher heat capacity. For a hotspot with a high power density of 5000 W cm(-2), the CNT microfins can cool down its temperature by more than 40 degrees C. The large heat dissipation capacity could make this cooling solution meet the thermal management requirement of the hottest electronic systems up to date.
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| 2. |
- Fu, Yifeng, 1984, et al.
(författare)
-
Application of through silicon via technology for in situ temperature monitoring on thermal interfaces
- 2010
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Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 1361-6439 .- 0960-1317. ; 20:2, s. id 025027 (5 pp)-
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a series of micro-machining processes have been developed to fabricate a test platform with the ability of in situ temperature monitoring on thermal interface behaviour. Through silicon vias (TSVs) with an aspect ratio up to 13 using Cu as a conductor have been applied to connect an array of platinum-based temperature sensors directly deposited on the thermal interfaces to be measured. The sensors are subsequently calibrated by an industry standard resistance temperature detector. Results show that the temperature sensors function normally in a temperature range up to 250 degrees C. This demonstrates the successful deposition of temperature-sensing materials and their good connection to the TSVs. The realization of direct precise temperature measurement on the thermal interface of this test platform enables thermal characterization with a high accuracy.
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| 3. |
- Fu, Yifeng, 1984, et al.
(författare)
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Selective growth of double-walled carbon nanotubes on gold films
- 2012
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Ingår i: Materials Letters. - : Elsevier BV. - 1873-4979 .- 0167-577X. ; 72, s. 78-80
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Tidskriftsartikel (refereegranskat)abstract
- Growth of high-quality vertical aligned carbon nanotube (CNT) structures on silicon supported gold (Au) films by thermal chemical vapor deposition (TCVD) is presented. Transmission electron microscopy (TEM) images show that the growth is highly selective. Statistical study reveals that 79.4% of the as-grown CNTs are double-walled. The CNTs synthesized on Au films are more porous than that synthesized on silicon substrates under the same conditions. Raman spectroscopy and electrical characterization performed on the as-grown double-walled CNTs (DWNTs) indicate that they are competitive with those CNTs grown on silicon substrates. Field emission tests show that closed-ended DWNTs have lower threshold field than those open-ended.
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| 4. |
- Fu, Yifeng, 1984, et al.
(författare)
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Templated Growth of Covalently Bonded Three-Dimensional Carbon Nanotube Networks Originated from Graphene
- 2012
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 24:12, s. 1576-1581
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Tidskriftsartikel (refereegranskat)abstract
- A template-assisted method that enables the growth of covalently bonded three-dimensional carbon nanotubes (CNTs) originating from graphene at a large scale is demonstrated. Atomic force microscopy-based mechanical tests show that the covalently bonded CNT structure can effectively distribute external loading throughout the network to improve the mechanical strength of the material.
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| 5. |
- Fu, Yifeng, 1984, et al.
(författare)
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Thick film patterning by lift-off process using double-coated single photoresists
- 2012
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Ingår i: Materials Letters. - : Elsevier BV. - 1873-4979 .- 0167-577X. ; 76, s. 117-119
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Tidskriftsartikel (refereegranskat)abstract
- A novel method using lift-off process for patterning very thick materials is developed and demonstrated. Unlike conventional lift-off processes, no special lift-off resist is used in this method. Instead, only a double-coated single photoresist is needed. Demonstrations using two commercial photoresists show that good patterning morphology and obvious undercuts as high as 15 mu m are obtained for lift-off, which is very difficult to achieve by existing methods. The application and feasibility of this approach is demonstrated by a carbon nanotube transfer process. This simple and effective method offers wider option to pattern very thick materials in high quality which are in strong demands.
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| 6. |
- Fu, Yifeng, 1984, et al.
(författare)
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Ultrafast Transfer of Metal Enhanced Carbon Nanotubes at Low Temperature for Large Scale Electronics Assembly
- 2010
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 22:44, s. 5039-5042
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Tidskriftsartikel (refereegranskat)abstract
- An indium-assisted ultrafast carbon nanotube (CNT) transfer method with a yield rate over 90% is described. Metal-coated as-transferred CNT structures exhibit excellent electrical performance that is at least one order of magnitude better than the previously published results. Shear test results show that the adhesion between CNTs and the substrate is greatly improved and excellent flexibility is obtained after the transfer process.
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| 7. |
- Hu, Zhili, 1983, et al.
(författare)
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Detecting single molecules inside a carbon nanotube to control molecular sequences using inertia trapping phenomenon
- 2012
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 101:13, s. Art. no. 133105-
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Tidskriftsartikel (refereegranskat)abstract
- Here we show the detection of single gas molecules inside a carbon nanotube based on the change inresonance frequency and amplitude associated with the inertia trapping phenomenon. As its directimplication, a method for controlling the sequence of small molecule is then proposed to realize theconcept of manoeuvring of matter atom by atom in one dimension. The detection as well as theimplication is demonstrated numerically with the molecular dynamics method. It is theoreticallyassessed that it is possible for a physical model to be fabricated in the very near future.
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| 8. |
- Xu, Liang, et al.
(författare)
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Effect of substrates and underlayer on CNT synthesis by plasma enhanced CVD
- 2013
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Ingår i: Advances in Manufacturing. - : Springer Science and Business Media LLC. - 2095-3127 .- 2195-3597. ; 1:3, s. 236-240
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Tidskriftsartikel (refereegranskat)abstract
- Due to their unique thermal, electronic and mechanical properties, carbon nanotubes (CNTs) have aroused various attentions of many researchers. Among all the techniques to fabricate CNTs, plasma enhanced chemical vapor deposition (PECVD) has been extensively developed as one growth technique to produce vertically-aligned carbon nanotubes (VACNTs). Though CNTs show a trend to be integrated into nanoelectromechanical system (NEMS), CNT growth still remains a mysterious technology. This paper attempts to reveal the effects of substrates and underlayers to CNT synthesis. We tried five different substrates by substituting intrinsic Si with high resistivity ones and by increasing the thickness of SiO2 insulativity layer. And also, we demonstrated an innovative way of adjusting CNT density by changing the thickness of Cu underlayer. © 2013 Shanghai University and Springer-Verlag Berlin Heidelberg.
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