Laskar Abhrajit, Shklyaev Oleg E, Balazs Anna C
Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Sci Adv. 2018 Dec 21;4(12):eaav1745. doi: 10.1126/sciadv.aav1745. eCollection 2018 Dec.
Catalyst-coated, hard particles can spontaneously generate fluid flows, which, in turn, propel the particles through the fluid. If the catalyst-coated object were a deformable sheet, then the self-generated flows could affect not only the sheet's motion but also its shape. By developing models that capture the interrelated chemical, hydrodynamic, and mechanical interactions, we uncover novel behavior emerging from the previously unstudied coupling between active, soft sheets and the surrounding fluid. The chemically generated flows "sculpt" the sheet into various forms that yield different functionalities, which can be tailored by modifying the sheet's geometry, patterning the sheet's surface with different catalysts, and using cascades of chemical reactions. These studies reveal how to achieve both spatial and temporal controls over the position and shape of active sheets and thus use the layers to autonomously and controllably trap soft objects, perform logic operations, and execute multistage processes in fluid-filled microchambers.
涂覆有催化剂的硬质颗粒能够自发地产生流体流动，而这种流体流动反过来又会推动颗粒在流体中运动。如果涂覆有催化剂的物体是一张可变形薄片，那么自生流动不仅会影响薄片的运动，还会影响其形状。通过建立能够捕捉相互关联的化学、流体动力学和机械相互作用的模型，我们发现了由活性软薄片与周围流体之间此前未被研究的耦合所产生的新行为。化学产生的流动将薄片“塑造”成各种具有不同功能的形状，这些功能可以通过改变薄片的几何形状、用不同催化剂对薄片表面进行图案化处理以及利用化学反应级联来进行定制。这些研究揭示了如何在空间和时间上对活性薄片的位置和形状进行控制，从而利用这些薄片在充满流体的微腔中自主且可控地捕获软物体、执行逻辑操作以及执行多阶段过程。
