Title: All-Optical Microfluidic Technology Enabled by Photodeformable Linear Liquid Crystal Polymers

Author: Lixin Jiang,  Lang Qin, Feng Pan, Yanlei Yu*

Journal: Acc. Mater. Res., 2025, ASAP

Abstract:

The microfluidic biochemical/immunoassay systems typically consist of microfluidic chips, fluid driving devices, and detection components. The core of the system is the microfluidic chips based on microfluidic technology, which are typically constructed with nonresponsive materials such as silicon, glass, and rigid plastics, thus requiring complex external air/liquid pumps to manipulate the samples. The external equipment renders the microfluidic systems cumbersome and increases the risk of biosample contamination. The all-optical microfluidic chip (AOMC) integrates all necessary microfluidic units and uses light to manipulate microfluids, which has the potential to completely solve the major problems of miniaturization and integration in microfluidic systems. The photocontrolled manipulation in AOMCs facilitates contactless interaction with liquids, eliminating the need for physical interconnects such as complex external electric, hydraulic, or pneumatic devices and replacing the traditional microfluidic components such as pumps, mixers, and separators, which offers AOMCs improved flexibility, robustness, and portability. However, impeded by photocontrolled principles and appropriate materials, AOMCs and photocontrolled biochemical/ immunoassay analyzers have never been created.

This Account highlights our efforts toward the new conception of all-optical microfluidic technology enabled by photodeformable linear liquid crystal polymers (LLCPs). We propose a novel mechanism to drive microfluids by the photoinduced Laplace pressure (asymmetric capillary force) and construct the first photodeformable 3D channel with newly designed photodeformable LLCPs possessing superior processability and photodeformability. The attenuated light is utilized to precisely control the axial asymmetric deformation of the 3D channels, which generates Laplace pressure, driving the fluids spontaneously toward the narrow end of the microtubes. Consequently, the photodeformable 3D channel integrates dual functions of the fluid channel and the pump, which is suitable for the construction of AOMCs, the core components of all-optical microfluidic technology, and lays the foundation for the miniaturization of microfluidic systems. By replacing the conventional chip materials with the photodeformable LLCPs, we construct the AOMC for the first time and achieve noncontact, accurate, and efficient manipulation of microfluids using a single light source, which plays an important role in solving the core conundrum of the cumbersome external equipment in the microfluidic chip systems. The AOMCs provide a robust platform for biochemical analysis such as protein detection and the catalytic oxidation reaction with minimal sample consumption, reduced reaction times, and enhanced portability, thus demonstrating the potential in in vitro detection with the ultratrace sample. Finally, we discuss the future challenges and opportunities inherent to all-optical microfluidic technology.

论文链接：https://pubs.acs.org/doi/10.1021/accountsmr.4c00318

PDF下载：All-Optical Microfluidic Technology Enabled by Photodeformable Linear Liquid Crystal Polymers.pdf

文章概述：

微流控生化/免疫分析系统通常由微流控芯片、流体驱动装置和检测装置构成。其中，微流控芯片作为系统的核心组件，通常采用硅、玻璃和塑料等非响应性材料构筑。然而，这类材料的特性决定了系统需要依赖复杂的外部泵阀装置来实现样品操控，因此系统集成度和操控灵活性受限。全光控微流体芯片（AOMC）利用光操控微流体，在芯片中集成所有必要的流体操控单元，为解决微流控系统在小型化和集成化方面的瓶颈提供了新的思路。AOMC中的光控液体运输机制实现了对液体的非接触式操控，有效简化系统架构并提升操控精度，显著提升了系统的灵活性、稳定性和便携性。然而，由于光控机制和适用材料的限制，AOMC及全光控生化/免疫分析仪器的研发至今仍面临巨大的挑战。在这篇综述中，我们总结了基于光致形变线型液晶高分子（LLCP）的全光控微流体技术研究进展，并且展望了该领域的应用前景以及潜在的研究方向。