Thermal gradient‐driven fluid motion, also known as thermal convection, is a common and significant phenomenon in nature. The utilization of localized thermal gradients to induce convection has emerged as a competitive approach in microfluidic chips. This technique enables the long‐distance transportation of substances under the influence of low‐power lasers. In this paper, an innovative optofluidic micro‐platform is presented that possesses a simple structure, easy operation, and excellent expandability. A UV nanosecond laser is utilized to create a high photothermal conversion region (HPCR) within the carbon nanotube‐doped PDMS substrate. Subsequently, the HPCR is subjected to irradiation for generating localized thermal gradients in the microfluidic chip. This resulted in Rayleigh–Bernard convection formation and facilitated long‐range transport and control of fluids and particles. Under low‐power laser irradiation, particles can be transported at speeds up to 0.18 mm s−1. In addition, the optofluidic platform shows significant potential for a range of functionalities, including fluid mixing and material sorting. The methodology described here allows for the rapid integration of new functionalities into existing chips while maintaining cost effectiveness and efficiency. This technique holds great promise for expanding the use of microfluidic devices in diverse fields, including chemistry, health sciences, materials science, and biomedicine.

中文翻译：

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通过热梯度驱动光流控增强微流控芯片功能

热梯度驱动的流体运动，也称为热对流，是自然界中常见且重要的现象。利用局部热梯度来诱导对流已成为微流控芯片中的一种有竞争力的方法。该技术可以在低功率激光的影响下实现物质的长距离运输。本文提出了一种创新的光流控微平台，具有结构简单、操作方便和良好的可扩展性。利用紫外纳秒激光在碳纳米管掺杂的 PDMS 基底内创建高光热转换区域 (HPCR)。随后，HPCR 受到照射以在微流控芯片中产生局部热梯度。这导致了瑞利-伯纳德对流的形成，并促进了流体和颗粒的远距离传输和控制。在低功率激光照射下，粒子的传输速度可达0.18 mm s−1。此外，光流控平台在一系列功能方面显示出巨大的潜力，包括流体混合和材料分类。这里描述的方法允许将新功能快速集成到现有芯片中，同时保持成本效益和效率。这项技术对于扩大微流体装置在化学、健康科学、材料科学和生物医学等不同领域的使用具有巨大的前景。