Magnetic field–induced droplet actuation has attracted substantial research interest in recent years. However, current magnetic-controlled liquids depend primarily on magnetic particles added to a droplet, which serves as the actuator on an open surface. These liquids inevitably suffer from droplet splitting with the magnetic particles or disengaging with the magnet, possibly leading to sample contamination, which severely limits their transport speed and practical applications. Here, we report a simple and additive-free method to fabricate magnetic tubular microactuators for manipulating liquid droplets by magnetism-induced asymmetric deformation, which generates an adjustable capillary force to propel liquids. These magnetic tubular microactuators can drive various liquid droplets with controllable velocity and direction. A speed of 10 cm s−1 can be achieved, representing the highest speed of liquid motion driven by an external stimulus–induced capillary force in a closed tube found so far.
展开▼
机译：近年来，磁场引起的液滴驱动引起了广泛的研究兴趣。然而，当前的磁控液体主要取决于添加到液滴中的磁性颗粒，该液滴充当开放表面上的致动器。这些液体不可避免地遭受液滴与磁性颗粒的分裂或与磁体的分离，从而可能导致样品污染，从而严重限制了其运输速度和实际应用。在这里，我们报告了一种简单且无添加剂的方法来制造磁性管状微致动器，以通过磁感应不对称变形来操纵液滴，从而产生可调节的毛细作用力来推动液体。这些磁性管状微致动器可以以可控制的速度和方向驱动各种液滴。可以达到10 cm s s -1 的速度，代表了迄今为止在封闭管中由外部刺激引起的毛细作用力驱动的最高液体运动速度。
展开▼
