The purpose of this study is to develop key components that can be used in a
magnetic resonance microsystem. Conventional magnetic resonance systems comprise
several components including a superconducting magnet, RF amplifier, spectrometer, and
probe head. This study proposes a magnetic resonance microsystem that uses NdFeB
permanent magnet material to replace the superconducting magnet, and an on-chip RF
amplifier and microfabricated coils as the probe head.
This study focuses on the design and fabrication of the key components of RF
microcoils and gradient microcoils. A multilayer high-aspect-ratio metal fabrication
process is developed to fabricate a nanoliter-volume radio frequency (RF) saddle coil
with an embedded flow-through fluidic channel for magnetic resonance applications. The
measured resistance of the RF microcoil and the 1H spectrum line width are 0.7 Ω and
350 Hz, respectively. The results indicate that this novel fabrication process for
microcoils is feasible for magnetic resonance applications. These key components can be
used to realize magnetic resonance microsystems in the future.

本論文之主要研究目的為開發可應用於微型化之核磁共振系統之關鍵零組件。傳統核磁共振系統包含了超導磁鐵、射頻放大訊號放大器、商用光譜儀、射頻探頭等元件。本研究所提出之微型化系統使用等級N42之銣鐵硼(NdFeB)材料組裝成永久磁鐵代替超導磁鐵，以及晶片化射頻放大器，和使用微製程所製造之射頻線圈及梯度線圈探頭。 本論文主要著重於射頻線圈和梯度線圈等關鍵元件之微型化設計與製造。微型化之射頻和梯度線圈使用多層高深寬比之金屬微製程技術所製造，在此微線圈中並製作一微流體通道使液體樣品流過。此微型射頻線圈之電阻值為0.7歐姆而在核磁共振實驗中量測得到的氫原子譜線寬度為350 Hz。本論文之研究結果顯示出利用上述之關鍵元件以實現微型化核磁共振系統之可行性。

List of Tables………………………………………………………………………..3
List of figures……………………………………………………………………….4
Chapter 1 Introduction……………………………………………………………...8
1.1 Historical Background……………………………………………………….....8
1.2 Purpose of Study………………………………………………………………..9
Chapter 2 NMR and MRI principles……………………………………………....11
2.1 The Principle of Nuclear Magnetic Resonance……………………………….11
2.2 Magnetic Resonance Image Principle and Gradient Coil……………………..18
Chapter 3 Microcoil……………………………………………………………….20
3.1 RF Coil design for miniaturization……………………………………………20
3.2 Gradient Coil…………………………………………………………………..25
3.3 Summary………………………………………………………………………29
Chapter 4 Finite Element Simulation of Microcoil……………………………….30
4.1 Magnetic Field Simulation of RF Coil………………………………………..30
4.2 Magnetic Field Simulation of Gradient Coil………………………………….33
Chapter 5 Fabrication Process of Microcoil………………………………………37
5.1 Solenoid Type Microcoil……………………………………………………...38
5.2 Polyimide Based Microcoi……………………………………………………41
5.3 Electrochemical Fabrication Process Microcoil……………………………...43
5.4 High Aspect Ratio Metal Coil Process………………………………………..48
5.5 Gradient Coil Process…………………………………………………………51
Chapter 6 Package Process of Microcoil………………………………………….53
6.1 Flow-Through Channel Fabrication Process………………………………….53
6.2 Selection of Package Material………………………………………………...57
2
Chapter 7 Microcoil Tests and Results……………………………………………59
7.1 RF Coil Measurements………………………………………………………..59
7.2 Gradient Coil Measurements………………………………………………….65
7.3 Discussion……………………………………………………………………..69
Chapter 8 Conclusions…………………………………………………………….73
Chapter 9 Future Work…………………………………………………………….74
References………………………………………………………………………....77
Appendix…………………………………………………………………………..80
A. RF IC Transceiver……………………………………………………………....80
B. Magnet…………………………………………………………………………..83
Author Curriculum Vitae…………………………………………………………..86

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