Action of low frequency vibration on liquid droplets and particles

Ultrasonics ◽  
2006 ◽  
Vol 44 ◽  
pp. e497-e502 ◽  
Author(s):  
J. Bennès ◽  
S. Alzuaga ◽  
P. Chabé ◽  
G. Morain ◽  
F. Chérioux ◽  
...  
Author(s):  
Matthew Trapuzzano ◽  
Nathan Crane ◽  
Rasim Guldiken ◽  
Andrés Tejada-Martínez

Abstract Adhesives, medical devices, and many cleaning products depend on the wetting of liquids on solid surfaces. The liquid/solid interaction depends on chemistry, surface topology, and external energy input. For instance, surfactants are commonly used in cleaning solutions to improve their effectiveness, and electrical fields are frequently used to control the contact angle of liquid droplets. Low frequency vibration has been used to spread, move, and manipulate droplets using the mode shape oscillations of the droplet to displace the contact line. Ultrasonic vibration (above 20 kHz) can also cause a liquid droplet to wet or spread out on a solid surface under the right circumstances. We have previously demonstrated that ultrasonic vibration can be used to control the wetting/spreading of liquid droplets on smooth hydrophobic surfaces and that the response is relatively insensitive to excitation frequency or fluid properties [1]. This paper reports on the use of ultrasonic vibration to initiate spreading on surfaces with etched pillars. Ultrasonic vibration successfully initiated a transition from Cassie to Wenzel states in all geometries with no apparent need to tune excitation frequencies to the geometry. However, the magnitude of the acceleration required to initiate the transition decreased with increased pillar spacing. For small pillar spacing, some smooth spreading in the Cassie wetting mode was observed before transition.


Author(s):  
K. Hama

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.


2021 ◽  
Vol 1104 (1) ◽  
pp. 012010
Author(s):  
Laxmi Devi ◽  
Kamlesh Paswan ◽  
Somnath Chattopadhyaya ◽  
Alokesh Pramanik

2011 ◽  
Vol 25 (5) ◽  
pp. 1231-1234 ◽  
Author(s):  
Gunawan Setia Prihandana ◽  
Muslim Mahardika ◽  
M. Hamdi ◽  
Kimiyuki Mitsui

2013 ◽  
Vol 475-476 ◽  
pp. 1624-1628
Author(s):  
Hasnizah Aris ◽  
David Fitrio ◽  
Jack Singh

The development and utilization of different structural materials, optimization of the cantilever geometry and power harvesting circuit are the most commonly methods used to increase the power density of MEMS energy harvester. This paper discusses the cantilever geometry optimization process of low power and low frequency of bimorph MEMS energy harvester. Three piezoelectric materials, ZnO, AlN and PZT are deposited on top and bottom of the cantilever Si substrate. This study focuses on the optimization of the cantilevers length, width, substrate thickness and PZe thickness in order to achieve lower than 600 Hz of resonant frequency. The harvested power for this work is in the range of 0.02 ~ 194.49 nW.


2010 ◽  
Vol 154-155 ◽  
pp. 166-170
Author(s):  
Gai Pin Cai ◽  
Ning Yuan Zhu ◽  
Na Wen

As a non-homogenous force stresses during incremental forming, sheet metal easily tended to instability, and some defects, such as deposition, wrinkle and fracture, would appear. If the vibration technique was combined the incremental forming process, its deformation mechanism would be different from that of the old process, and sheet metal deformation quality was also risen. Then some mechanical equations were built by force analyzed on element in local contact zone of die head forcing down. According to reasonable hypothesis and simplified, the equations were solved. Some stress-time curves of the element were obtained by given process parameters, vibrational parameters and time parameters. It is shown from analysis that stress variety of the element is closely related to amplitude, frequency and forming angle, effect of sheet metal vibration incremental forming with high frequency vibration is more superior than that of with low frequency vibration; only when vibrational parameters are reasonably matching technical parameters, the effective vibration incremental forming can be obtained.


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