Title Page
Contents
ABSTRACT 7
Ⅰ. Introduction 8
Ⅱ. Materials and Methods 12
2.1. Device fabrication 12
2.2. Device structure 13
2.3. Experimental setup and instruments 13
2.4. Working principle 14
Ⅲ. Theoretical modeling of viscosity measurement 16
Ⅳ. Results and discussion 18
4.1. Decreasing stepwise pressure generator operation 18
4.2. Variable resistance 18
4.3. Testing of the stepwise flow rate 21
4.4. Fluidic resistor 21
4.5. Viscosity measurement 22
Ⅴ. Conclusion 24
References 25
Abstract (in Korean) 27
〈Figure 2-1〉 Working mechanism of the stepwise decreasing pressure generator and variable fluidic resistor (a) conceptual diagram to show the... 15
〈Figure 3-1〉 Flow curves to show concept of measuring viscosity (1) for Newtonian liquids as viscosity is constant of varying shear rate (2) for non-... 17
〈Figure 4-1〉 Experimental pressure profile of the stepwise decreasing pressure generator with step size (210 Pa) and duration time (~70s). 18
〈Figure 4-2〉 Electronic-fluidic analogy of fluidic resistor (a) microfluidic chip of fluidic resistor (b) electronic circuit corresponding with microfluidic chip. 19
〈Figure 4-3〉 Result of pressure P by changing the valve seat and membrane thickness. 20
〈Figure 4-4〉 Result of corresponding resistance Rv by changing the valve seat and membrane thickness.[이미지참조] 20
〈Figure 4-5〉 Flow rate responds with stepwise pressure by manually varing Pb. (a) stepwise pressure (b) stepwise flow rate.[이미지참조] 21
〈Figure 4-6〉 The operation of fluidic resistor (a) decreasing stepwise pressure converts to increasing pressure as the working of fluidic resistor (b) amplifies... 22
〈Figure 4-7〉 Viscosity analysis of DI water (a) increasing pressure P at variable valve position (b) measured flow rate Q using flow sensor (c) viscosity... 23