미세관 내의 음파 전달 현상을 이용한 마이크로 점도계의 개발과 그 설계 기술의 응용

Abstract

A novel micro-viscometer was designed and fabricated to measure the viscosity variation in minimal amounts of liquid in real-time. It was developed to evaluate the physical characteristics of liquids that are easily changeable and/or for those of which a large sample is difficult to obtain, such as with biomaterials. The micro-viscometer can detect the viscosity variation of a liquid sample of no more than 13 . It is composed of a dual chamber with four microchannels connecting each chamber, and fabricated using MEMS (Micro-Electro-Mechanical System) technology. Each chamber has a unimorphic piezoelectric diaphragm for generating and sensing sound waves. Viscosity variation is rapidly measured by detecting the output to input signal ratio on condition of continuous or tone burst single-frequency input driven to the actuator. The performance of the micro-viscometer was verified by experimentation on test samples of various viscosities. Subsequently, using the experimental results from the micro-viscometer, a study on the propagation of acoustic waves in a microchannel was undertaken, since it had not yet been proved experimentally and the micro-viscometer had the appropriate structure to execute the study. The experimental results were compared to the simulated results to confirm that the continuum based acoustic theory can be applied to explain the propagation of acoustic waves in a microchannel.