| Wed September 14th 2016 16:30 – 17:00 ZH286 | Seminar | The rectified motion of a shaken drop Maxime Costalonga |
Details:The manipulation of droplets has been a fast-growing challenge in the last decades, together with microfluidics, in order to optimise processes such as biomedical tests using only volumes of fluid in the nanoliter scale. To handle such quantities, using vibrations is a quite versatile way since it allows to mix, move and even atomise droplets as their power increases. In this study, we focus on the motion of drops submitted to vibrations along an oblique axis. We show that the coupling of two eigenmodes of the drop is necessary to displace it. Depending on the excited modes, therefore on the frequency, it is possible to adjust the velocity of the drop, and even to choose the direction of its motion. Moreover, we reveal that viscosity discriminates two regimes associated to different types of friction undergone by the drop. Finally, we take a closer look at the oscillations of the contact line, showing that even when it moves continuously without pinning, an effect of contact angle hysteresis can still arise. We conclude by enumerating several possible applications illustrating the wealth of such simple experiment of drop shaking, such as sorting or separating droplets. | ||
