摘 要

人工纤毛阵列能够实现微流体管道中的流体定向运输和微区混合等作用，受到人们广泛关注。现有的人工纤毛阵列存在着制备受模板限制和功能单一的问题，本文提出采用3D打印与紫外光固化成型的方法，将一维磁性光子晶体软链固定在玻璃基板上，实现磁驱人工纤毛阵列的图案化和可控化制备。Fe₃O₄@PVP超顺磁纳米粒子为光子链的基本组成单元，在磁场和紫外光的作用下通过模板聚合法将形成的一维有序结构封装在具有pH响应的聚合物即聚（丙烯酸-共-甲基丙烯酸羟乙酯）P(AA-co-HEMA)中。同时，由于聚合物中的羧基与表面含有氨基的正电玻璃基板之间具有较强的氢键吸附作用，因此单体聚合也可以发生在光子链和玻璃基板之间，最终能够形成这种一端固定在基板上另一端可以在磁场下自由旋转的链结构。于是，在外加旋转磁场的诱导下，该磁驱人工纤毛阵列可以产生流体的定向流动。根据布拉格方程可知，通过聚合的收缩膨胀,光子链会发生衍射峰的变化，具体表现在暗场下反射颜色的变化。所以，该磁驱人工纤毛阵列还能够实时的监测微区环境pH值变化，使得该人工纤毛具有感知能力。

论文主要研究了不同Fe₃O₄@PVP粒子浓度对光子链长度和接枝在基板上密度的影响，不同表面性质的玻璃基板对Fe₃O₄@ P(AA-co-HEMA)光子链阵列“打印”的影响和Fe₃O₄@ P(AA-co-HEMA)光子链阵列的货物输运及传感性能。通过分析实验数据可知，随着Fe₃O₄@PVP磁性粒子浓度提高，接在玻璃基板上的光子链的长度和密度会随着提高。采用具有合适的接触角以及表面富含氨基的玻璃基板能够得到线宽均匀的打印图案以及适当接枝密度的光子链阵列。在外加偏心旋转磁场的诱导下，光子链阵列会进行非对称的锥形旋转运动，在链顶端附近产生的定向流体流动能够引导货物的定向运输。同时，当输运的货物能够释放离子改变局部环境pH值时，该光子链阵列可以进行实时观察。

本文特色在于首次采用3D打印成型的方法，在玻璃基板上制备出线宽均一、图案可控的磁驱人工纤毛阵列，该纤毛阵列在外加磁场的诱导下不仅具备定向运输微纳米货物的特点，同时还具备微区pH传感的能力。

关键词：光子链，人工纤毛阵列，pH传感，磁驱

Abstract

Artificial cilia arrays are new developed microfluidic devices which can be used to control direct the microfluid and mix them up. Their extraordinary performance catches comprehensive attention. But, due to the fact that so far artificial cilia arrays have always been limited to its synthesis substrate and simple function which focus on its motile property, in this paper a new swift 3-dimensional printed method with UV solidifying has been introduced to fix the 1-dimensional magnetic soft photonic crystals nanochains on the glass slide, therefore, it can precisely control the process of magnetic artificial cilia arrays and swiftly print it in program-designed patterns. The fundamental unit of photonic nanochains are Fe₃O₄@PVP superparamagnetic particles. By the substrate polymerization with external magnetic field and UV illumination, the surface of photonic nanochains are blocked by the copolymer network of poly (AA-co-HEMA), in which the carboxyl groups are able to build hydrogen bonds with the hydroxyl groups on the positive-surface substrate. Via these bonds, the artificial cilia fix rapidly onto the substrate. After these constructions, one end of photonic nanochain is strongly stick on the glass slide and the above part can freely rotate according to magnetic field. Base on this magnetic property, under the guidance of external revolving magnetic field, these magnetic artificial cilia arrays are spurred to produce directed microfluid, which means the directed transportation of targeted micro-cargos can be implemented. In addition, the connect bonds in copolymer networks are sensitive to the pH value, which means that the length of bonds will alter itself with the environment changing. In other words, according to Brag laws, with the polymers convergent-divergent, the wavelength of diffraction light in photonic nanochains will response to pH changes of the bulk and we can simply observe this color varying of cilia arrays by microscope in dark field illumination. Consequently, these magnetic artificial cilia arrays are equal to monitor pH values in micro environment in real time, in other words, they have sensitive property.

This paper mainly focuses on a magnetic-controlled photonic artificial cilia arrays with its attractive printing fabrication technique, sensing and transportation properties. The influence of Fe₃O₄@PVP superparamagnetic particles’ concentration on length and fixation concentration of photonic nanochains, different glass slides with varied surface properties on printing results, pH sensing property and targeted cargo transportation behaviors of the magnetic-controlled photonic artificial cilia arrays have be investigated. The experimental data demonstrates that both the length and density of photonic nanochains will increase with magnetic Fe₃O₄@PVP particle concentration. with amino-groups on its surface, the positive charged glass slide who has an appropriate contact angle will be the most beneficial substrate for print a uniform width pattern within suitable fixation concentration of artificial cilia arrays. Furthermore, with the guidance of external decentered revolving magnetic field, the photonic cilia arrays will start asymmetrical and periodical beats to direct microfluidics as well as the targeted cargo. In the meantime, if the cargos release some ions which can change pH value in microfluidics, we can monitor this influence in real time due to the sensitive properties of cilia arrays.

The characteristic of this work lies in that a magnetic-controlled artificial photonic artificial cilia with controllable and uniform width pattern, as well as it’s a facile “printing” fabrication technique that has been demonstrated for the first time. Not only do these artificial cilia arrays actualize the directed cargo transportations, but also possess the pH sensation property.

Keywords: Photonic nanochains, Artificial cilia arrays, pH response, Magnetic actuation 目 录

第1章 绪论 5

1.1 人工纤毛阵列在微流体环境中的潜力 6

1.2 人工纤毛阵列种类 6

1.2.1 电场驱动型人工纤毛阵列 6

1.2.2 磁场驱动型人工纤毛阵列 8

1.2.3 其它驱动类型人工纤毛阵列 11

1.3 研究目的及意义 12

第2章 Fe₃O₄@P(AA-co-HEMA)光子链的制备和表征 13

2.1实验部分 13

2.1.1 实验仪器 13

2.1.2 实验药品 13