Driving Wetting Transitions on Textured Surfaces Using Ultrasonic Vibration

2020 ◽  
Author(s):  
Matthew Trapuzzano ◽  
Nathan Crane ◽  
Rasim Guldiken ◽  
Andrés Tejada-Martínez
Keyword(s):  
Ultrasonic Vibration ◽  
Liquid Droplet ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Surface Topology ◽  
Liquid Droplets ◽  
Textured Surfaces ◽  
External Energy ◽  
Low Frequency Vibration ◽  
The Right

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.

scholarly journals Low-Frequency Vibration Sensor with a Sub-nm Sensitivity Using a Bidomain Lithium Niobate Crystal

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 614 ◽  
Author(s):  
Ilya Kubasov ◽  
Aleksandr Kislyuk ◽  
Andrei Turutin ◽  
Alexander Bykov ◽  
Dmitry Kiselev ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Vibration Sensor ◽  
Gravitational Acceleration ◽  
Frequency Sensor ◽  
Linear Behavior ◽  
Low Frequency Vibration ◽  
Acceleration Amplitude ◽  
Vibrational Excitations

We present a low-frequency sensor for the detection of vibrations, with a sub-nm amplitude, based on a cantilever made of a single-crystalline lithium niobate (LiNbO3) plate, with a bidomain ferroelectric structure. The sensitivity of the sensor-to-sinusoidal vibrational excitations was measured in terms of displacement as well as of acceleration amplitude. We show a linear behavior of the response, with the vibrational displacement amplitude in the entire studied frequency range up to 150 Hz. The sensitivity of the developed sensor varies from minimum values of 20 μV/nm and 7 V/g (where g = 9.81 m/s2 is the gravitational acceleration), at a frequency of 23 Hz, to peak values of 92.5 mV/nm and 2443 V/g, at the mechanical resonance of the cantilever at 97.25 Hz. The smallest detectable vibration depended on the excitation frequency and varied from 100 nm, at 7 Hz, to 0.1 nm, at frequencies above 38 Hz. Sensors using bidomain lithium niobate single crystals, as sensitive elements, are promising for the detection of ultra-weak low-frequency vibrations in a wide temperature range and in harsh environments.

205201 Study on Reduction of Residual Stress in Welded Joint Using Low Frequency Vibration : Effect of Excitation Frequency

2011 ◽  
Vol 2011.17 (0) ◽  
pp. 139-140
Author(s):  
Shigeru Aoki ◽  
Tadashi Nishimura ◽  
Tetsumaro Hiroi ◽  
Seiji Hirai ◽  
Katsumi Kurita ◽  
...  
Keyword(s):  
Residual Stress ◽  
Welded Joint ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Vibration Effect ◽  
Low Frequency Vibration

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 ◽  
...  
Keyword(s):  
Low Frequency ◽  
Liquid Droplets ◽  
Low Frequency Vibration

Prevention of Delamination during Drilling of Composite Material Using Vibration

2004 ◽  
Vol 261-263 ◽  
pp. 381-386 ◽  
Author(s):  
Shigeru Aoki ◽  
Toshiyasu Nishimura
Keyword(s):  
Composite Material ◽  
Ultrasonic Vibration ◽  
Analytical Method ◽  
Low Frequency ◽  
Adhesive Layer ◽  
Experimental Results ◽  
Vibrational Load ◽  
Low Frequency Vibration ◽  
Prevention Method

Prevention method of delamination at adhesive layer during drilling of composite material using vibration is examined. First, this method is examined experimentally. As vibrational load, relatively low frequency vibration and ultrasonic vibration are used. It is concluded occurrence of delamination is less when vibration is used during drilling. Next, experimental results are examined by analytical method. Adhesive layer is assumed to be damping component. Condition of occurrence of delamination is proposed.

scholarly journals Dynamic Parameter Optimization and Experimental Study of Tuned Slab Damper on Metro Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Guang-Hui Xu
Keyword(s):  
Parameter Optimization ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Dynamic Parameter ◽  
Complex Method ◽  
Low Frequency Vibration ◽  
Track System ◽  
Train Operation ◽  
Metro Systems ◽  
Set Up

With the increase of axle weight and speed, the interaction between vehicles and the track becomes more and more intense, and the problem of wheel-rail dynamic action is more serious. In order to reduce the low-frequency vibration caused by train operation, a three-layer elastic track damping structure is proposed. The complex method is used to optimize the dynamic parameters, structural patterns, and coupling relations of the track structure, which allows multiple elastic units to work in harmony with each other to achieve the effects of absorbing vibration energy and reducing vibration transmission. Finally, a real size model experimental platform is set up to verify the dynamic parameter optimization results. The results show that the vertical mode of the main track system of the coupling-tuned slab damper-floating slab is 26.898 Hz close to the train excitation frequency, and the corresponding equivalent mass is 6074.53 kg. The amplitude of the vibration components in the 20∼40 Hz band can be reduced to 41.8% by using the complex method. The maximum insertion loss is about 10 dB, and the vibration of low-frequency band is not amplified.

Broadband and Low Frequency Vibration-Based Energy Harvesting Improvement Through Magnetically Induced Frequency Up-Conversion

2010 ◽  
Author(s):  
Adam M. Wickenheiser
Keyword(s):  
Energy Harvester ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Beam Theory ◽  
Magnetic Interaction ◽  
Large Mass ◽  
Stochastic Simulations ◽  
Base Excitation ◽  
Low Frequency Vibration ◽  
Compact Design

In order to extract as much energy as possible from ambient vibrations, many vibration-based energy harvesters (VEHs) are designed to resonate at a specific base excitation frequency. Unfortunately, many vibration energy sources are low frequency (0.5 Hz–100 Hz), intermittent, and broadband. Thus, resonant VEHs would not be excited continuously and would require a large mass or size to tune to such a low frequency. This work presents the modeling, analysis, and experimental application of a nonlinear, magnetically excited energy harvester that exhibits efficient broadband, frequency-independent performance. This design utilizes a passive auxiliary structure that remains stationary relative to the base motion of the VEH. This device is especially effective for driving frequencies well below its fundamental frequency, thus enabling a more compact design compared to traditional resonant topologies. A mechanical model based on Euler-Bernoulli beam theory is coupled to a linear circuit and a model of the nonlinear, magnetic interaction to produce a distributed parameter magneto-electromechanical system. The results of both harmonic and broadband, stochastic simulations demonstrate multiple-order-of-magnitude power harvesting performance improvement at low driving frequencies and an insensitivity to time-varying base excitation frequency content. Furthermore, the proposed system is shown to enable more practical designs than a resonant energy harvester for the specific example of harvesting energy from walking motion.

Broadband Low-Frequency Vibration Energy Harvester with a Rolling Mass

2013 ◽  
Vol 404 ◽  
pp. 635-639 ◽  
Author(s):  
Xue Feng He ◽  
You Zhu ◽  
Yao Qing Cheng ◽  
Jun Gao
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Maximum Output Power ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Vibration Energy ◽  
Maximum Output ◽  
Vibration Energy Harvester ◽  
Low Frequency Vibration ◽  
Half Power

Richness of broadband low-frequency vibration energy in environemnts makes it significant to develop broadband low-frequency vibration energy harvesters. A vibration energy harvester composed of two symmetrical cantilevered piezoelectric bimorphs and a rolling mass in a guiding channel was proposed. A prototype of the vibration energy harvester with a rolling mass was assembled and tested. The base excitation caused the rolling mass to impact with two cantilevered bimorphs repeatedly and the impacts cause the bimorphs to vibrate dramatically. Experimental results show that maximum output power and corresponding excitation frequency increased with the amplitude of base acceleration. For the prototype, the maximum output power of a piezoelectric bimorph on a resistor with the resistance of 100 kΩ was 602 μW under base acceleration with the amplitude of 1.5 g and frequency of 37 Hz, and the half power bandwidth was about 13.5% or 5 Hz.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

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.

The Occlusion Effect in Unilateral Functional Hearing Loss

1970 ◽  
Vol 13 (1) ◽  
pp. 37-40
Author(s):  
Gary Thompson ◽  
Marie Denman
Keyword(s):  
Hearing Loss ◽  
Bone Conduction ◽  
Low Frequency ◽  
Clinical Implications ◽  
The Right ◽  
Occlusion Effect

Bone-conduction tests were administered to subjects who feigned a hearing loss in the right ear. The tests were conducted under two conditions: With and without occlusion of the non-test ear. It was anticipated that the occlusion effect, a well-known audiological principle, would operate to draw low frequency bone-conducted signals to the occluded side in a predictable manner. Results supported this expectation and are discussed in terms of their clinical implications.

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