A Novel CMOS Sensor for Measuring Thermal Diffusivity of Liquids with a Transient Method
Date Issued
2006
Date
2006
Author(s)
Chung, Ya-Rui
DOI
en-US
Abstract
The purpose of this thesis is to design a novel microdevice for measuring the thermal diffusivity of a liquid droplet in small amounts. CMOS chip is fabricated by TSMC 0.35μm 2P4M CMOS process and post-CMOS micromachining processes are proceeded. The CMOS chip consists of a thin film of polysilicon that covers a cavity of the substrate. The thin film has a rectangular centered heater and four temperature sensors surrounding the heater. Once a known voltage is applied to the heater, the thermal diffusivity of liquid drop that spreads over the heater and the temperature sensors can be determined from the measured temperature responses at different locations of the temperature sensors. The thermal diffusivity of liquid drop that spreads over the heater and the temperature sensors can be determined from the measured temperature responses at an impulse voltage. The simulation and experimental results illustrate that the higher thermal diffusivity of liquid causes lower maximum temperature change.
Thermal diffusivity of other liquids could be measured as well based on a relation between thermal diffusivity by measuring procedure in the thesis.
Subjects
CMOS
熱擴散係數
ANSYS
後製程
thermal diffusivity
post-CMOS micromachining
Type
thesis