光响应液晶高分子新材料及其生物微流控芯片构筑

The core value of microfluidic chips is their applications in the field of modern bioscience. However, the existing microfluidic biochips are made of non-responsive materials, such as PDMS, therefore it is impossible to realize the spontaneous motion of the microfluid in the channels and thus complex lines and cumbersome pumps are necessary to be connected to the chips to realize the manipulation of liquids, which is the key problem for the integration and simplification of the microfluidic biosystems. Recently, based on the photoresponsive linear liquid crystal polymer (LCP), we have fabricated light-controllable self-driven tubular microactuators, in which complex liquids were precisely propelled under light irradiation without any aid of lines and pumps. This kind of tubular microactuators presents a conceptually novel way to propel liquids by capillary force arising from photo-induced asymmetric deformation. In a word, we provides a kind of new material and new mechanism for the simplification of microfluidic systems. In this project, we aim at the manufacturing upgrade from microtubes to microfluidic chips. Firstly, a series of photoresponsive linear LCPs with different structures will be prepared by ring-opening metathesis polymerization to optimize mechanical properties, processing properties and photoresponsiveness. Secondly, we plan to improve wettability and biocompatibility of the LCPs by surface modification and coating to achieve the LCPs in accordance with the physiological characteristics of biological molecules; then we are going to select suitable processing methods to fabricate microfluidic biochips based on photoresponsive LCPs. At last, we will try to realize the precise light control on the transportation of biological samples in microfluidic channels, which is an important foundation for promoting the applications of light-controlled microfluidic technology in the biological field.

微流控芯片在现代生物科学领域的应用是其最核心的价值体现，然而目前均使用PDMS等非响应性的材料来构筑微流控生物芯片，无法实现微流体在通道内的自发运动，需要连接复杂的外部驱动设备，难以将微流控系统集成并简化。近年来我们利用液晶高分子智能光响应材料构筑出自驱动的光控微型管状系统，利用其光致形变产生的轴向毛细力，实现了对于各种复杂流体的高效输运，为微流控系统的简化提供了全新的材料和驱动机制。本项目针对微管执行器到微流控芯片的制造升级开展研究，拟利用开环易位聚合制备一系列不同结构的线型光响应液晶高分子，实现材料机械性能、加工性能以及光响应性能的优化；通过表面修饰及涂覆技术调控亲疏水性和生物相容性等，构筑符合生物分子生理特性的液晶高分子材料体系；优选出配套的加工方法构筑基于光响应液晶高分子的微流控生物芯片，并实现芯片通道中生物样品输运的精确光控制，为推动光控微流体技术在生物领域的应用奠定重要基础。

微流控技术广泛应用于生化分析、疾病诊断、环境检测等领域，具有高通量、快检测、少浪费、集成化等优势。但是目前微流控系统的外部控制体系的简化成为制约其发展的瓶颈问题，因此亟需一种全新的驱动、控制机制打破这一瓶颈让微流控系统真正达到微型化。光致形变液晶高分子材料在微流体操控领域的应用为突破这一瓶颈提供了全新思路，该材料可以将光能直接转化为微量液体的动能，免去外部复杂驱动设备，有利于微流控系统的集成和简化，并可以实现微流体的远程、非接触、定点精确控制。由光致形变液晶高分子材料制备的光控微流控芯片具有更易微型化、便携化、精度高等优点。我们在前期新一代光致形变高分子构筑的微管执行器的基础上，推动微管执行器到微流控芯片的升级制造，探索其在生化、免疫检测领域的潜在应用。.通过本项目的研究，我们面向生物样品检测的需求研制了一系列具有良好机械性能、光致形变性能、加工性能和生物相容性的光响应液晶高分子新材料，并开发了一系列与之适配的加工工艺，进一步发展了材料微观结构与宏观特异性形变之间构-效关系理论，为新型光流控器件的研发奠定了材料基础。通过将新型光响应线型液晶高分子材料与光控液体运输的机理相结合，开发了模板法、复合构筑工艺等新型加工和制备策略，建立了适配生物微流控芯片构筑的标准化加工工艺与制程，构筑了能够实现光控液体运输的柔性复合微管执行器以及光流控芯片等一批新型原型器件，实现了液体操控体积从微升级到纳升级的跨越，为光流控设备迈向小型化、智能化、可穿戴化及功能多样化奠定了结构基础。基于流体力学计算与仿真模拟，优化光流控芯片结构，实现全光控的微纳升液体的运输、融合、分离等基础功能单元的构建，并利用各个单元的集成与整合，完成芯片中全光控微量蛋白样品检测，推动新型全光控微流控设备向小型化、功能化、实用化的发展。.在本项目资助下，共发表学术论文31篇，包括2篇Adv. Mater.、3篇Adv. Funct. Mater.、1篇Nat. Commun.、1篇Small等。申请中国发明专利2项，其中授权1项，申请已授权美国发明专利1项。相关研究成果“光响应高分子材料”获得上海市自然科学奖一等奖（本项目负责人为第一完成人）。