Testing of thermal micro-actuator of polymer composite

• Main Author: Teo, Yu Hao.
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Mechanical engineering::Control engineering
• Online Access: http://hdl.handle.net/10356/45689
• Institution: Nanyang Technological University

A new class of thermal micro-actuators has been developed based on a multi-material composite, which consists of a silicon skeleton, a SU-8 epoxy thermal expander and an aluminium heater. As a composite, it has room for performance improvements by design. The performance of these micro-actuators is determined by their ability to expand under heat, namely the coefficient of linear thermal expansion (CTE). The CTE refers to how much a material will expand per degree of temperature, and can be expressed as a ratio of change in length to the product of initial length and change in temperature. The CTE was evaluated by recording the changes in lengths during heating. Comparisons of results using different magnifications were performed. In total, nine samples were tested and the best three sample results were selected. On average, results showed coefficients of thermal expansion between 2.7x10-5 K–1 to 3.4x10-5 K–1, which was in the expected range. The actuator is a very important part of the hard disk that partakes in the function and performance of the drive. Hence, improvements in the actuator design are critical to enhancing the seek time of a hard disk.