| 1. |
- Fu, Yifeng, 1984, et al.
(författare)
-
Templated Growth of Covalently Bonded Three-Dimensional Carbon Nanotube Networks Originated from Graphene
- 2012
-
Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 24:12, s. 1576-1581
-
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.
|
|
| 2. |
- Fu, Yifeng, 1984, et al.
(författare)
-
A complete carbon-nanotube-based on-chip cooling solution with very high heat dissipation capacity
- 2012
-
Ingår i: Nanotechnology. - : IOP Publishing. - 1361-6528 .- 0957-4484. ; 23:4
-
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.
|
|
| 3. |
- Wang, Shun, et al.
(författare)
-
MDS study on the adhesive heat transfer in micro-channel cooler
- 2010
-
Ingår i: Proceedings - 2010 11th International Conference on Electronic Packaging Technology and High Density Packaging, ICEPT-HDP 2010; Xi'an; 16 August 2010 through 19 August 2010. - 9781424481422 ; :Article number 5583859, s. 630-633
-
Konferensbidrag (refereegranskat)abstract
- Carbon nanotube (CNT) can be used in micro-channel cooler construction due to its excellent thermal conductivity. When fabricating CNTs directly onto the chip, the chip could be damaged because of the high temperature required for CNT growth (about 750°C). As a solution, a transfer technique is developed where the desired carbon nanotube pattern can be obtained by taking off a pre-fabricated CNT forest with a designed adhesive, and the transfer process could make the chip or other components immune from the high temperature required for the CNT growth process. This process can also improve the bonding/adhesive strength. Nevertheless, the use of adhesive in the CNT-based micro-channel structure might affect the thermal conduction of the cooling system. In particular, the heat transfer between the heat generator and the CNT fin in the micro-channel cooler shall be evaluated. In this paper the thermal conductivity of the adhesive is studied by molecular dynamics simulation (MDS). The adhesive considered in the present MDS model consists of the epoxy and the curing agent. After the curing process, the epoxy molecules construct a network, which is established in the epoxy matrix generation before the simulation. Nonequilibrium Molecular Dynamics Method (NEMD) is adopted in the modeling and periodic boundary conditions are applied. Furthermore, the heat transfer through CNT and adhesive interface is simulated in this work based on the adhesive results, which can provide information for future macro-analysis of the thermal performance of the CNT microchannel cooler. © 2010 IEEE.
|
|
| 4. |
- Zhang, Yong, 1982, et al.
(författare)
-
Improved Thermal Properties of Three-Dimensional Graphene Network Filled Polymer Composites
- 2022
-
Ingår i: Journal of Electronic Materials. - : Springer Science and Business Media LLC. - 1543-186X .- 0361-5235. ; 51:1, s. 420-425
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents the improved thermal property of three-dimensional (3D) graphene network modified polydimethylsiloxane (PDMS) composites. It shows that with a 2 wt.% loading of graphene foams (GF), the thermal conductivity of GF/PDMS composite was successfully increased from 0.19 W/mK to 0.42 W/mK, which is 2.2 times higher than that of neat PDMS. However, if GF was transformed into graphene sheets (GS) by sonication, the thermal conductivity of GS/PDMS was decreased to 0.28 W/mK. The remarkable improvement of the thermal properties is attributed to the 3D interconnected graphene network in GF, which form continuous heat transfer networks. Furthermore, the finite element analysis was conducted to evaluate the effect of GFs in composites, where some parameters such as thickness and thermal conductivity were analyzed and discussed. Our results indicate that the continuous 3D GFs holds great potential as fillers to improve the thermal property of polymer materials.
|
|
| 5. |
- Zhang, Y., et al.
(författare)
-
Molecular dynamics simulation for the bonding energy of metal-SWNT interface
- 2011
-
Ingår i: Proceedings - 12th International Conference on Electronic Packaging Technology and High Density Packaging, ICEPT-HDP 2011, Shanghai, 8-11 August 2011. - 9781457717680 ; , s. 506-509
-
Konferensbidrag (refereegranskat)abstract
- For this paper, we carried out molecular dynamics simulation to calculate the bonding energy of the metal-SWNT interface. Three kinds of metal, namely iron, nickel and gold, were studied. The results show that the iron-SWNT interface has the strongest bonding energy, and then nickel and gold. To confirm these results, tensile loading tests were also performed to study the breaking force of the metal-SWNT interface. The force needed to debond the metal-SWNT interface is at the order of nano-newton. The more adhesion energy the interface has, the bigger force that must be loaded to break the joint.
|
|
