- 學位論文
新型微流體晶片透過層流之特性篩選並分離精蟲
Sorting and Separation Sperms based on a Novel Laminar-Stream-Based Microfluidic Chip
摘要
本論文提出一微尺度層流篩選精蟲之晶片系統，能針對原始精蟲濃度、活動力不同的樣本進行一次性篩選，而無須因個體間樣本差異性而更換晶片或作不同程度的稀釋。本晶片係採軟微影技術以聚二甲基矽氧烷 (Polydimethylsiloxanes, PDMS) 翻模後與玻片接合而成，具低成本、高精密度、可量產、可拋棄、及製程簡易等特性，皆符合生醫晶片的需求。此外在製程上，本研究創新採用PDMS與厚膜光阻結構接合後共同構成母膜的技術，能輕易做出具高深寬比且不影響流道結構精密度的母膜。 自體外受精技術及卵細胞質內單一精蟲顯微注射術發展以來，人工協助生殖技術已成為醫學領域近十年重要的一環。細胞質內單一精蟲顯微注射術主要透過挑選單一精蟲直接注入卵細胞，故著重於其內遺傳物質正常；體外受精技術則透過樣本前處理，於體外讓一群精蟲與卵細胞自然受精，二者間的碰撞頻率扮演關鍵角色，故精蟲的活動力、總數量、濃度等因素將直接影響受精結果。透過微機電製程不易分辨遺傳物質正常與否，卻很有機會透過生物晶片於樣本前處理階段篩選出最適合進行體外受精的精蟲。 本研究共分二階段，第一階段完成一微尺度層流篩選精蟲晶片系統，主要針對精蟲活動力進行篩選，其中包含晶片設計、流場模擬、以及實際以公豬精液樣本測試的結果等，其內容詳述於第三章。第二階段則延續第一階段的研究進一步改良晶片，透過轉折流道增加篩選效率，其內容詳述於第四章。最後本論文於第五章提出部分未來可望加以思考的方向。
並列摘要
The thesis presents a novel microfluidic based sperm sorting system that the whole process can be done in only one step. The difference in sperm motility or concentration between raw semen samples can be ignored before the sorting process using this device. The fabrication process of our bio-chip include SU8 thick-film photolithography and soft-lithography, which has the advantages of low-cost, high-precision, volume production, disposable, and easy to produce etc., so that it is suitable for biomedical chip. Besides, the new idea that combines both SU-8 structure and PDMS part to construct the mode have the advantage that high aspect ratio structure can be easily made without losing the precision of micro flow channel. Since the emerging of in vitro fertilization (IVF) technology and intracytoplasmic sperm injection (ICSI), assisted reproductive technology (ART) has become an important part of medical field over the past 10 years. ISCI technology focus on the genetic normality of sperm, because the process consist the direct injection of a single sperm into an oocyte; IVF technology is an natural in vitro fertilization process that come after a series of sample pre-treatment. Since the frequency of collisions between sperms and oocytes plays a key role in the fertilization, the semen property, including motility, total number, and the concentration of sperms, will directly affect the outcome. It is difficult to determine whether the genetic materials is normal or not through micro electro mechanical system (MEMS) technology, but there is a good opportunity to use a MEMS based biochips to selected the most suitable sperms before IVF process. The study is divided into two parts. In the first part, the goal is to construct a microfluidic based sperm sorting system, which focus on the screening and the classification based on sperm motility. The details including chip design, flow field simulation, and the experiments of boar semen samples are show in chapter 3. The second part improves the screening efficiency using disjunctive design, which is present in chapter 4. At the end, some ideas of future works were proposed in Chapter 5.