Chong Matthew Lai Ho, Cheng Michael, Katariya Mayur, Muradoglu Murat, Cheong Brandon Huey-Ping, Zahidi Alifa Afiah Ahmad, Yu Yang, Liew Oi Wah, Ng Tuck Wah
Laboratory for Optics and Applied Mechanics, Department of Mechanical & Aerospace Engineering, Monash University, VIC3800, Clayton, Australia.
Biomechanics and Biomaterials Laboratory, Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, 100081, Beijing, China.
Eur Phys J E Soft Matter. 2015 Nov;38(11):119. doi: 10.1140/epje/i2015-15119-y. Epub 2015 Nov 20.
We advance a scheme in which a liquid body on a stationary tip in contact with a rotating superhydrophobic surface is able to maintain resonance primarily from stick-slip events. With tip-to-surface spacing in the range 2.73 ≤ h < 2.45 mm for a volume of 10 μL, the liquid body was found to exhibit resonance independent of the speed of the drum. The mechanics were found to be due to a surface-tension-controlled vibration mode based on the natural frequency values determined. With spacing in the range 2.45 ≤ h < 2.15 mm imposed for a volume of 10 μL, the contact length of the liquid body was found to vary with rotation of the SH drum. This was due to the stick-slip events being able to generate higher energy fluctuations causing the liquid-solid contact areas to vary since the almost oblate spheroid shape of the liquid body had intrinsically higher surface energies. This resulted in the natural frequency perturbations being frequency- and amplitude-modulated over a lower frequency carrier. These findings have positive implications for microfluidic sensing.
我们提出了一种方案，在该方案中，位于固定尖端上与旋转的超疏水表面接触的液体能够主要通过粘滑事件来维持共振。对于10 μL的体积，当尖端到表面的间距在2.73≤h<2.45 mm范围内时，发现液体表现出与鼓的速度无关的共振。根据所确定的固有频率值，发现其力学原理是基于表面张力控制的振动模式。对于10 μL的体积，当施加的间距在2.45≤h<2.15 mm范围内时，发现液体的接触长度随超疏水鼓的旋转而变化。这是因为粘滑事件能够产生更高的能量波动，导致液 - 固接触面积发生变化，因为液体的近似扁球体形状本身具有更高的表面能。这导致固有频率扰动在较低频率载波上进行频率和幅度调制。这些发现对微流体传感具有积极意义。
