University of Calgary PRISM: University of Calgary's Digital Repository Graduate Studies The Vault: Electronic Theses and Dissertations 2012-09-06 Development of a low cost micro-pump Khalilian, Sina Khalilian, S. (2012). Development of a low cost micro-pump (Unpublished master's thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/25658 http://hdl.handle.net/11023/179 master thesis University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Downloaded from PRISM: https://prism.ucalgary.ca UNIVERSITY OF CALGARY Development of a Low Cost Micro-pump by Sina Khalilian A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE DEPARTMENT OF MECHANICAL AND MANUFACTURING ENGINEERING CALGARY, ALBERTA Aug, 2012 © Sina Khalilian 2012 i UNIVERSITY OF CALGARY FACULTY OF GRADUATE STUDIES The undersigned certify that they have read, and recommend to the Faculty of Graduate Studies for acceptance, a thesis entitled “ Development of a Low Cost Micro-pump” submitted by Sina Khalilian in partial fulfilment of the requirements for the degree of the degree of Master of Science. ________________________________________________ Supervisor, Dr. Theodor Freiheit Department of Mechanical & Manufacturing Engineering ________________________________________________ Dr. Robert W. Brennan Department of Mechanical & Manufacturing Engineering ________________________________________________ Dr. Alejandro Ramirez-Serrano Department of Mechanical & Manufacturing Engineering ________________________________________________ Dr. Colin Dalton Department of Electrical & Computer Engineering ______________________ Date ii Abstract There is a growing demand for micro-pumps as a subcomponent in micro-fluidic systems. In order to make micro-pumps more suitable for most of cost-sensitive mass applications such as micro cooling systems, fuel cells and disposable biomedical applications, a design targeted toward lowest manufacturing cost, high endurance, and reliability is devised for the micro- pump. In this work, a check-valve micro-pump with a piezoelectric motivator was selected as a low cost design. By following a modular design approach, the total number of parts to be manufactured is minimized. This design is composed of four parts, the upper and lowers casing halves, a single plate inlet and outlet valve, and a piezoelectric disc. To achieve high durability and reliability, stainless steel shim stock was selected as the valve material. Micro- injection moulding and chemical etching processes were selected for the fabrication processes of the casings and the valve, respectively. Also, to facilitate the assembly process and for sealing the micro-pump casing, a heat press method of assembly was designed and tested. To predict performance of the micro-pump, a modular simulation model was developed. In this model, results from static flow testing of the micro-valves, piezoelectric displacement test, and finite element structural analysis were incorporated in the model. As a result, a practical model for predicting the micro-pump performance at operating frequencies below 50 Hz is achieved. This simulation model can be useful in parameter selection, optimization and also micro-valve selection for different application requirements of the micro-pump. As a result of this work, by applying design for manufacturing and mass fabrication methods to the overall micro-pump design, a low cost micro-pump designed for high performance and useful to a variety of applications is obtained. iii Acknowledgements I would like to thank Dr. Theodor Freiheit and Dr. Simon Park for their constant support, guidance and encouragements. At all the stages of this project I benefited from their advices. Dr. Theodor Freiheit’s positive outlook, patience and confidence in my research inspired me and gave me confidence. His careful editing contributed enormously to the production of this thesis. I want to express my thanks to Mr. Mehdi Mahmoodi, Mr. Chaneel Park and Mr. Liam Hagel and other members of the Micro Engineering, Dynamics and Automation Laboratory for their support to this project. I also would like to thank the Micro Systems Technology Research Initiative (MSTRI) of the Governments of Canada and Alberta, and the University of Calgary for their support of this project. Finally, I would like to thank the Advanced Micro-nanosystems Integration Facility (AMIF at the University of Calgary) for assistance in fabrication the valves, as well as the Alberta Innovates Technology Futures (AITF), nanoAlberta program, to AMIF for equipment-related financial assistance. iv Table of Contents Approval Page..................................................................................................................... ii Abstract ............................................................................................................................. iii Acknowledgements............................................................................................................ iv Table of Contents................................................................................................................v List of Tables......................................................................................................................ix List of Figures.................................................................................................................... xi Chapter 1: INTRODUCTION ......................................................................................... 1 1.1 Introduction .................................................................................................................. 1 1.2 Motivation .................................................................................................................... 2 1.3 Objectives and Approaches.......................................................................................... 6 1.4 Organization ................................................................................................................. 9 Chapter 2: Review of Micro-pump Technology ........................................................... 11 2.1 Displacement - Reciprocating micro-pumps ............................................................. 12 2.1.1 Driving mechanisms ........................................................................................... 13 2.1.1.1 Piezoelectric Motivators ........................................................................ 14 2.1.1.2 Electrostatic Motivators ........................................................................ 15 2.1.1.3 Electromagnetic Motivators .................................................................. 17 2.1.1.4 Shape memory alloys (SMA) motivator ............................................... 18 2.1.1.5 Pneumatic and Thermo-pneumatic Motivators ..................................... 19 2.1.2 Micro-valve mechanisms for controlling backflow ........................................... 21 2.1.2.1 Passive valves ........................................................................................ 21 2.1.2.2 Active valves ......................................................................................... 22 2.1.2.3 Dynamic Valves .................................................................................... 23 2.2 Displacement- Rotary and Peristaltic Micro-pumps .................................................. 25 v 2.2.1 Micro Gear Pump ............................................................................................... 26 2.2.2 Peristaltic Micro-pump ....................................................................................... 28 2.2.3 Other displacement micro-pumps ....................................................................... 29 2.3 Dynamic- Non Mechanical Micro-pumps ................................................................. 30 2.3.1 Electro-hydrodynamic (EHD) ............................................................................ 31 2.3.2 Electro-osmotic ................................................................................................... 31 2.3.3 Magneto-hydrodynamic...................................................................................... 32 2.3.4 Ultrasonic ........................................................................................................... 33 2.4 Comparison and evaluation of the Micro-pump driving mechanisms ....................... 34 2.5 Diaphragm micro-pump simulation and analysis ...................................................... 36 2.6 Micro-pump Manufacturing Methods ....................................................................... 40 2.6.1 Photolithographic processes ............................................................................... 41 2.6.1.1 Wet (Chemical) Etching ........................................................................ 41 2.6.1.2 Dry etching methods ............................................................................. 42 2.6.2 Micro-Injection Moulding .................................................................................. 43 2.6.3 Micro-milling ....................................................................................................