Swimming by reciprocal motion at low Reynolds number.
Swimming by reciprocal motion at low Reynolds number.
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DOI：
10.1038/ncomms6119
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发表时间：
2014-11-04
影响因子：
16.6
通讯作者：
Fischer, Peer
中科院分区：
文献类型：
--
作者：
Qiu, Tian;Lee, Tung-Chun;Mark, Andrew G.;Morozov, Konstantin I.;Muenster, Raphael;Mierka, Otto;Turek, Stefan;Leshansky, Alexander M.;Fischer, Peer
生物微生物游动的鞭毛和纤毛执行非往复运动的低雷诺数（Re）推进粘性流体。这种对称性要求是珀塞尔扇形定理的结果，这使得微泳者所需的驱动方案变得复杂。然而，大多数生物医学上重要的流体是非牛顿流体，其中扇贝定理不再成立。因此，应该可以实现在非牛顿流体中以往复周期性体型变化移动的微型游泳器。在这里，我们报告了一个对称的“微扇贝”，一个单铰链microswimmer，可以推动在剪切增稠和剪切变稀（非牛顿）流体在低Re的往复运动。我们的测量结果与数值和分析理论预测之间的良好一致性表明，净推进力是由流体粘度的调制引起的，在不同的剪切速率。这种往复游动机制为设计生物医学微器件提供了新的可能性，这些微器件可以通过简单的驱动方案在非牛顿生物流体中推进。 能够导航生物医学流体和组织的操作设备是微型机器人的最终目标之一。虽然目前的设计仅限于非往复致动，但Qiu等人报告了通过利用粘性流体的非牛顿流变学经由简单往复运动的游泳。
Biological microorganisms swim with flagella and cilia that execute nonreciprocal motions for low Reynolds number (Re) propulsion in viscous fluids. This symmetry requirement is a consequence of Purcell’s scallop theorem, which complicates the actuation scheme needed by microswimmers. However, most biomedically important fluids are non-Newtonian where the scallop theorem no longer holds. It should therefore be possible to realize a microswimmer that moves with reciprocal periodic body-shape changes in non-Newtonian fluids. Here we report a symmetric ‘micro-scallop’, a single-hinge microswimmer that can propel in shear thickening and shear thinning (non-Newtonian) fluids by reciprocal motion at low Re. Excellent agreement between our measurements and both numerical and analytical theoretical predictions indicates that the net propulsion is caused by modulation of the fluid viscosity upon varying the shear rate. This reciprocal swimming mechanism opens new possibilities in designing biomedical microdevices that can propel by a simple actuation scheme in non-Newtonian biological fluids. Operating devices that can navigate biomedical fluids and tissues is one of the ultimate goals of microrobotics. Whilst the current designs are restricted to non-reciprocal actuations, Qiu et al. report swimming via simple reciprocal motion by exploiting the non-Newtonian rheology of viscous fluids.
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影响因子：
64.8
作者：
Dreyfus, R;Baudry, J;Bibette, J
通讯作者：
Bibette, J
影响因子：
41.2
作者：
Mark, Andrew G.;Gibbs, John G.;Fischer, Peer
通讯作者：
Fischer, Peer
影响因子：
0.9
作者：
PURCELL, EM
通讯作者：
PURCELL, EM
DOI：
10.1007/s00542-007-0430-1
发表时间：
2008-03-01
影响因子：
2.1
作者：
Guo, Shuxiang;Pan, Qinxue;Khamesee, Mir Behrad
通讯作者：
Khamesee, Mir Behrad
影响因子：
4.6
作者：
Montenegro-Johnson, Thomas D.;Smith, David J.;Loghin, Daniel
通讯作者：
Loghin, Daniel