High Speed Paraffin Nanocomposite Phase Change Microactuator for Microvalve Applications

• Author / Creator

  Movahedian, Samira

• Microvalves are an essential part of microfluidic systems for chemical and biological analysis. However, the lack of high performance materials has hindered the development of microactuators capable of driving valves with combined rapid response and high closing forces. Paraffin-based phase change microvalves achieve high open/close flow ratios and closing pressures, which minimize leakage. In addition, they are stable and easy to fabricate. However, these valves are intrinsically slow, due to the low thermal conductivity of paraffin coupled to its high specific heat capacity. We report on a rapid response phase change microactuator for microvalve applications based on a polymer membrane and a novel composite of paraffin and high thermal conductivity nanoparticles. By modifying the thermal properties of paraffin, faster heat transfer and actuation speed can be achieved. This design can be used to fabricate microvalves in contamination-sensitive lab-on-chip (LOC) systems where low leakage and high speed flow control are required.

• Subjects / Keywords

  • Microactuator
  • Paraffin
  • Phase-change
  • Microvalve
  • SU-8
  • Nanocomposites

• Graduation date

  Fall 2012

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3470H

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.