复杂流体中Janus微马达自扩散泳特性的实验研究

Janus微纳马达在生物医学中作为药物输运的载体或在复杂工况中作为微纳机器人的动力部件具有广阔的应用前景。已有研究主要集中于Janus微纳马达在水溶液等简单流体中的运动，而对其在复杂流体中的运动机理及特性的研究仍非常缺乏。通过实验测量了直径2.06 μm的Janus球形微马达在高聚物聚氧化乙烯（PEO）溶液中的自扩散泳特性，实验结果系统描述了高聚物质量分数对Janus微马达自扩散泳速度、运动均方位移（MSD）及转动特性的影响。实验结果显示:高聚物的加入，不仅会影响溶液黏度，还会导致自驱动MSD在短时间段显示亚扩散特性，在推进段显示随高聚物质量分数改变的超扩散特性，甚至还会导致反常的微马达旋转加快现象。

Experimental study on the self-diffusiophoresis of the Janus micromotor in complex fluids

Janus micro/nanomotors have shown broad application prospects as drug delivery tools in biomedicine or energy generators for micro/nano-robots working under complex conditions. Existing studies have focused on the self-diffusiophoresis of Janus micro/nanomotors in simple liquids such as water, however, the research on the mechanism and characteristics of the self-diffusiophoresis in complex fluids is still lacking. This work experimentally investigates the self-diffusiophoresis of 2.06 μm Janus micromotors in polymer PEO solutions. The results systematically describe the influence of the PEO concentration on the propulsion speed of the Janus micromotor, the mean square displacements of the motion, and the rotation feature. Our findings show that the PEO polymers not only influence the viscosity of the solution, but also cause sub-diffusive and super-diffusive behaviors in the short-time and intermediate-time propulsion regime respectively, and result in an anomalous enhancement of the rotation of the Janus micromotors.