0
Research Papers: Micro/Nanoscale Heat Transfer

Thermal Actuation Using Nanocomposites: A Computational Analysis

Y. Xu and G. Li
[+] Author and Article Information
Y. Xu

 Department of Mechanical Engineering, Clemson University, Clemson, SC 29634

G. Li1

 Department of Mechanical Engineering, Clemson University, Clemson, SC 29634gli@clemson.edu

1

Corresponding author.

J. Heat Transfer 134(11), 112401 (Sep 28, 2012) (11 pages) doi:10.1115/1.4007128 History: Received April 04, 2011; Revised June 04, 2012; Published September 26, 2012; Online September 28, 2012

In this paper, we propose the use of Si/Ge nanocomposite materials to improve the performance of microthermal actuators. Nanocomposites with a high electrical to thermal conductivity ratio can facilitate a rapid temperature change within a short distance, enabling a high temperature increase in a large region of the actuator beams. The total structural thermal expansion and, consequently, the actuation distance can be increased significantly. A top-down quasi-continuum multiscale model is presented for the computational analysis of nanocomposite based thermal actuators. In the multiscale model, the thermo-mechanical response of the actuator due to Joule heating is modeled using classical continuum theories, while the thermal and electrical properties of doped Si and Si/Ge nanocomposite materials are obtained from atomistic level descriptions. An iterative procedure is carried out between the calculations at the two length scales until a self-consistent solution is obtained. Numerical results indicate that incorporating Si/Ge nanocomposites in thermal actuators can significantly increase their energy efficiency and mechanical performance. In addition, parametric studies show that the size of the nanocomposite region and atomic percentage of the material components have significant effects on the overall performance of the actuators.

Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 7

Variation of phonon thermal conductivity of Si1− x Gex nanocomposites at 300 K with respect to the atomic percentage of Ge

Grahic Jump Location
Figure 8

Temperature-dependent electrical conductivity of the Si70 Ge30 alloy and the Si80 Ge20 nanocomposites

Grahic Jump Location
Figure 9

Temperature-dependent electrical conductivity of the Si1− x Gex nanocomposites for different atomic percentages of Ge

Grahic Jump Location
Figure 10

Temperature distribution variation with respect to the length of the nanocomposite part and the atomic percentage of Ge in Si1− x Gex

Grahic Jump Location
Figure 6

Strain and temperature dependent phonon thermal conductivity of the Si80 Ge20 nanocomposite between 300 K–800 K

Grahic Jump Location
Figure 5

Strain and temperature dependent phonon thermal conductivity of bulk Si between 300 K –800 K

Grahic Jump Location
Figure 4

Linear thermal expansion coefficient of Si1− x Gex between 300 K– 800 K

Grahic Jump Location
Figure 3

Elastic constants of Si1− x Gex

Grahic Jump Location
Figure 11

Tip displacement of the V-shaped TA as a function of the length of the nanocomposite part and the atomic percentage of Ge in Si1− x Gex

Grahic Jump Location
Figure 12

Variation in the temperature distribution along the V-shaped TA beam with respect to the length of the Si80 Ge20 nanocomposite

Grahic Jump Location
Figure 13

Maximum displacement of the V-shaped TA for different lengths of the Si80 Ge20 nanocomposite

Grahic Jump Location
Figure 14

Temperature distribution along the V-shaped TA beam for different atomic percentages of Ge in Si1− x Gex (Lc  = 200 μm)

Grahic Jump Location
Figure 15

Maximum displacement of the V-shaped TA for different atomic percentages of Ge in Si1− x Gex

Grahic Jump Location
Figure 2

Si1− x Gex unit cell

Grahic Jump Location
Figure 1

(a) V-shaped actuator, (b) U-shaped actuator, and (c) Si/Ge nanocomposite material

Grahic Jump Location
Figure 16

Variation of the temperature distribution along the upper beam of the U-shaped TA with the length of the Si/Ge nanocomposite and the Ge atomic percentage

Grahic Jump Location
Figure 17

Maximum vertical displacement of the U-shaped TA as a function of the length of the Si/Ge nanocomposite for different Ge atomic percentages

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In