開發可應用於生物樣品機械性質量測之微流體元件

Abstract

生物樣本之物理特性例如：組織之彈性、血液的黏滯度與骨骼之硬度等，對細胞、組織之功能以及生物反應有著關鍵的影響，其中，彈性係數為最重要的特性之一，在細胞變形、遷移、分化以及反應的過程中，細胞外基質以及細胞本身的機械強度以及相互造成的形變皆會彼此交互影響、控制細胞的行為，並可能更進一步影響疾病的生成或是改變生理的功能。本論文將開發微流體元件以應用於生物樣品的機械性質量測，第一與第二部份分別針對在模擬體內微觀環境下培養的橫觀等向性以及橫觀異向性細胞生物樣品之機械性質進行量測。本研究中利用微流體裝置以及內嵌式壓力感測器建構可用於量測非等向性之細胞層於平面方向上的楊氏模數，並結合生物原子力顯微鏡對細胞層面外方向的楊氏模數進行量測。於實驗量測中，本論文先針對肺泡上皮細胞在有無癌化基因過度表達條件下細胞層之面內楊氏模數進行探討，接著探討血管內皮細胞經流體剪切應力排列後之內皮細胞層於面內平行以及垂直細胞排列方向上之楊氏模數。實驗結果顯示，本研究中開發之微流體感測晶片可量測生物樣本之物理特性並應用於對其病理機制進行更深入的研究中。此外，血管中血液黏性也和心血管疾病有著非常密切的關係，因此本論文第三部份中利用微流體裝置搭配布拉格光纖光柵（FBG）感測器設計一可用於量測非牛頓流體之黏滯係數之感測器，此感測器透過量測流體在不同流速下流動時產生之壓力差，並利用布拉格光纖光柵之中心波長的變化量得到壓力差的大小，進而計算出流體之黏滯係數。本論文中成功利用自行開發之微流體元件對非等向性細胞樣本以及細胞外基質之楊氏模數進行量測，並利用生物用原子力顯微鏡進行量測作為比較。此外，本研究中亦開發可應用於量測牛頓以及非牛頓流體之黏滯係數的微流體感測器，未來可望應用於生物基礎研究以及臨床篩檢與監測之工具。

The physical properties of biological samples—such as tissue elasticity, blood viscosity, and bone hardness—play a critical role in determining cellular function, tissue behavior, and physiological responses. Among these properties, the elastic modulus is particularly important, as it influences cellular deformation, migration, differentiation, and overall biomechanical interactions between cells and the extracellular matrix (ECM), potentially affecting disease progression and physiological functions. This study aims to develop microfluidic devices for measuring the mechanical properties of biological samples. The first and second parts of the thesis focus on measuring the mechanical characteristics of transversely isotropic and anisotropic cell samples cultured in biomimetic microenvironments. A microfluidic platform integrated with embedded pressure sensors was designed to measure the in-plane Young’s modulus of anisotropic cell layers, while atomic force microscopy (AFM) was employed to assess the out-of-plane stiffness. The experiments first investigated the in-plane elastic properties of alveolar epithelial cell layers with and without oncogene overexpression. Subsequently, the study examined the anisotropic elastic properties of vascular endothelial cell layers aligned under controlled shear stress, comparing Young’s modulus along and perpendicular to the alignment direction. Results demonstrated that the developed microfluidic sensing chip effectively characterizes the mechanical properties of biological samples and supports advanced research on pathological mechanisms. Given the strong correlation between blood viscosity and cardiovascular diseases, the third part of this thesis presents a novel microfluidic viscometer integrated with a fiber Bragg grating (FBG) sensor for measuring the viscosity of non-Newtonian fluids. By analyzing pressure differentials generated at varying flow rates and correlating them with the Bragg wavelength shifts, fluid viscosity can be accurately derived. In conclusion, this work successfully demonstrates the use of self-developed microfluidic platforms to measure the anisotropic elasticity of cell layers and ECM, validated by AFM measurements. Additionally, the proposed FBG-based microfluidic sensor for non-Newtonian fluid viscosity measurement shows promise for future applications in both fundamental biomedical research and clinical diagnostics.