Affiliation:
1. Department of Mechanical Engineering, Stanford University, Stanford, CA 94305
Abstract
An accurate measurement of the thermophysical properties of freestanding thin films is essential for modeling and predicting thermal performance of microsystems. This paper presents a method for simultaneous measurement of in-plane thermal conductivity and heat capacity of freestanding thin films based on the thermal response to a sinusoidal electric current. An analytical model for the temperature response of a freestanding thin film to a sinusoidal heating current passing through a metal heater patterned on top of the thin film is derived. Freestanding thin-film samples of silicon nitride and nickel titanium (NiTi), a shape memory alloy, are microfabricated and characterized. The thermal conductivity of thin-film NiTi, which increases linearly between 243K and 313K, is 40% lower than the bulk value at room temperature. The heat capacity of NiTi also increases linearly with temperature in the low temperature phase and is nearly constant above 280K. The measurement technique developed in this work is expected to contribute to an accurate thermal property measurement of thin-film materials. Thermophysical measurements on NiTi presented in this work are expected to aid in an accurate thermal modeling of microdevices based on the shape memory effect.
Subject
Mechanical Engineering,Mechanics of Materials,Condensed Matter Physics,General Materials Science
Reference38 articles.
1. Thin-Film Shape Memory Alloy Actuated Micropumps;Benard;J. Microelectromech. Syst.
2. Silicon Hotplates for Metal Oxide Gas Sensor Elements;Sberveglieri;Microsyst. Technol.
3. Micromachined Pressure Sensors: Review and Recent Developments;Eaton;Smart Mater. Struct.
4. Shape Memory Microvalves Based on Thin Films or Rolled Sheets;Kohl;Mater. Sci. Eng., A
5. Thin Film Shape-Memory Alloy Micro-Actuators;Krulevitch;J. Microelectromech. Syst.
Cited by
110 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献