Ultrasonic manipulation of particles

• Main Author: Huang, Jing Fen.
• Other Authors: Hu Junhui
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Control and instrumentation::Control engineering
• Online Access: http://hdl.handle.net/10356/40787
• Institution: Nanyang Technological University

Ultrasonic manipulation of small particles is an exceptionally useful technique in handling of biological cells such as DNA and protein molecules. Collection, separation and transportation of small particles have been realized by means of ultrasonic techniques. In this Final Year Project, 2 different ultrasonic devices, Dual Aluminium Strip Ultrasonic Actuator and Acoustic Needle Ultrasonic Transducer, were examined to determine their trapping capability and the affecting factors. For the Dual Aluminium Strip, a modified design from the previous work was fabricated and tested on. The trapping capability of the Dual Aluminium Strip was deemed to be weaker than the previous model. Further investigation on the vibration displacement of the metal strips was carried out and it was concluded that a big difference in the strength of the acoustic radiation force between the new and earlier designs existed. For the Acoustic Needle, experiments were conducted to determine the trapping force of the ultrasonic transducer at different needle length. Various factors that would influence the trapping capability of the ultrasonic transducer were also explored. After completing the series of experiment, it was found out that the trapping capability at various needle lengths followed certain pattern. From this pattern, a maximum and minimum trapping force can be realized by adjusting the length of the needle. Factors that will influence the performance of the ultrasonic transducer include the input voltage, frequency of the input voltage and the orientation of the needle.