Using laser Doppler vibrometry to measure capillary surface waves on fluid-fluid interfaces

Friend, James; Yeo, Leslie

doi:10.1063/1.3353329

Cited by 13 publications

(8 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Potentially, the drop could be restrained with a well, but this may introduce a different boundary condition and additional complications in its excitation and was not considered here. However, the electrical power used to drive the drop vibration is generally less than 1 W. 12 A laser Doppler vibrometer (LDV) (MSA-400, Polytec, Waldbronn, Germany) was used to measure the vibration velocity spectrum of the fluid surface 49 along the axis of the laser's path at its intersection with the measurement surface; the diameter of the measured area is approximately 1 μm. 49 This technique has several advantages over alternatives: high sensitivity (to O(1 pm)); broad measurement range of DC to 25 MHz, where direct imaging or the measurement of scattering through the surface 35 would require extremely high camera frame rates and correspondingly high-intensity illumination; and noncontact measurement, where other techniques in use require intrusive capacitive probes 19 that would distort the geometry of the drop.…”

Section: ■ Generating and Measuring Microscale Capillary Wavesmentioning

confidence: 99%

Microscale Capillary Wave Turbulence Excited by High Frequency Vibration

Blamey

Yeo²,

Friend

2013

Langmuir

View full text Add to dashboard Cite

Low frequency (O(10 Hz−10 kHz)) vibration excitation of capillary waves has been extensively studied for nearly two centuries. Such waves appear at the excitation frequency or at rational multiples of the excitation frequency through nonlinear coupling as a result of the finite displacement of the wave, most often at one-half the excitation frequency in so-called Faraday waves and twice this frequency in superharmonic waves. Less understood, however, are the dynamics of capillary waves driven by high-frequency vibration (>O(100 kHz)) and small interface length scales, an arrangement ideal for a broad variety of applications, from nebulizers for pulmonary drug delivery to complex nanoparticle synthesis. In the few studies conducted to date, a marked departure from the predictions of classical Faraday wave theory has been shown, with the appearance of broadband capillary wave generation from 100 Hz to the excitation frequency and beyond, without a clear explanation. We show that weak wave turbulence is the dominant mechanism in the behavior of the system, as evident from wave height frequency spectra that closely follow the Rayleigh−Jeans spectral response η ≈ ω −17/12 as a consequence of a period-halving, weakly turbulent cascade that appears within a 1 mm water drop whether driven by thickness-mode or surface acoustic Rayleigh wave excitation. However, such a cascade is one-way, from low to high frequencies. The mechanism of exciting the cascade with high-frequency acoustic waves is an acoustic streaming-driven turbulent jet in the fluid bulk, driving the fundamental capillary wave resonance through the well-known coupling between bulk flow and surface waves. Unlike capillary waves, turbulent acoustic streaming can exhibit subharmonic cascades from high to low frequencies; here it appears from the excitation frequency all the way to the fundamental modes of the capillary wave at some four orders of magnitude in frequency less than the excitation frequency, enabling the capillary weakly turbulent wave cascade to form from the fundamental capillary wave upward.

show abstract

Section: ■ Generating and Measuring Microscale Capillary Wavesmentioning

confidence: 99%

Microscale Capillary Wave Turbulence Excited by High Frequency Vibration

Blamey

Yeo²,

Friend

2013

Langmuir

View full text Add to dashboard Cite

show abstract

“…The following day the cured PDMS were removed from the silicon substrate and then punched to form around 14 mm circles. The surfaces were cleaned with 70% ethanol, three distilled water rinses, and then allowed to air dry in a clean environment 24 , 28 , 29 .…”

Section: Methodsmentioning

confidence: 99%

Silk films with nanotopography and extracellular proteins enhance corneal epithelial wound healing

Luo

Kang

Sartaj

et al. 2021

Sci Rep

View full text Add to dashboard Cite

Corneal wound healing depends on extracellular matrix (ECM) and topographical cues that modulate migration and proliferation of regenerating cells. In our study, silk films with either flat or nanotopography patterned parallel ridge widths of 2000, 1000, 800 nm surfaces were combined with ECMs which include collagen type I (collagen I), fibronectin, laminin, and Poly-d-Lysine to accelerate corneal wound healing. Silk films with 800 nm ridge width provided better cell spreading and wound recovery than other size topographies. Coating 800 nm patterned silk films with collagen I proves to optimally further increased mouse and rabbit corneal epithelial cells growth and wound recovery. This enhanced cellular response correlated with redistribution and increase in size and total amount of focal adhesion. Transcriptomics and signaling pathway analysis suggested that silk topography regulates cell behaviors via actin nucleation ARP-WASP complex pathway, which regulate filopodia formation. This mechanism was further explored and inhibition of Cdc42, a key protein in this pathway, delayed wound healing and decreased the length, density, and alignment of filopodia. Inhibition of Cdc42 in vivo resulted in delayed re-epithelization of injured corneas. We conclude that silk film nanotopography in combination with collagen I constitutes a better substrate for corneal wound repair than either nanotopography or ECM alone.

show abstract

“…Commercial LDVs often employ a Mach-Zehnder interferometer [ Fig. 8(a)] and usually allow characterising the motion of a fluid-fluid interface at frequencies of up to 100 MHz and displacements of as little as a few tens of picometres [124]. Oscillations of the droplet can be excited by either a thicknessmode piezoelectric transducer [PZT, see Fig.…”

Section: Fig 6: Comparison Between (A) a Theoretical Capillary Oscilmentioning

confidence: 99%

“…An acousto-optic modulator (AOM) is used to permit measurement of the objects vibration phase by shifting the reference lasers wavelength by a fixed amount. Reprinted with permission from [124]. (b) Schematic of a thickness-mode PZT.…”

Section: Fig 7: the Interaction Of Light With Different Modes Of Thementioning

confidence: 99%

Coupling light and sound: giant nonlinearities from oscillating bubbles and droplets

Maksymov

Greentree

2019

Nanophotonics

View full text Add to dashboard Cite

Nonlinear optical processes are vital for fields including telecommunications, signal processing, data storage, spectroscopy, sensing, and imaging. As an independent research area, nonlinear optics began with the invention of the laser, because practical sources of intense light needed to generate optical nonlinearities were not previously available. However the high power requirements of many nonlinear optical systems limit their use, especially in portable or medical applications, and so there is a push to develop new materials and resonant structures capable of producing nonlinear optical phenomena with low-power light emitted by inexpensive and compact sources. Acoustic nonlinearities, especially giant acoustic nonlinear phenomena in gas bubbles and liquid droplets, are much stronger than their optical counterparts. Here, we suggest employing acoustic nonlinearities to generate new optical frequencies, thereby effectively reproducing nonlinear optical processes without the need for laser light. We critically survey the current literature dedicated to the interaction of light with nonlinear acoustic waves and highly-nonlinear oscillations of gas bubbles and liquid droplets. We show that the conversion of acoustic nonlinearities into optical signals is possible with low-cost incoherent light sources such as lightemitting diodes, which would usher new classes of low-power photonic devices that are more affordable for remote communities and developing nations, or where there are demanding requirements on size, weight and power. . 1: (a) Generation of new optical frequencies via a nonlinear optical interaction. High-power monochromatic laser light interacts with the nonlinear optical medium, e.g. a dielectric microresonator, to generate new optical frequencies [9]. (b, c) The nonlinear properties of sound can be used to generate optical nonlinearities without the need for high-power laser light. Low-power light couples to a sound wave via a deformable fluid, e.g. gas bubble or liquidmetal nanoparticle, exploiting strong nonlinear acoustic effects. This converts acoustic frequencies to the optical domain, effectively reproducing the result of the nonlinear optical interaction in (a). Images from www.freeimages.com and www.dreamstime.com. FIG

show abstract

Using laser Doppler vibrometry to measure capillary surface waves on fluid-fluid interfaces

Cited by 13 publications

References 38 publications

Microscale Capillary Wave Turbulence Excited by High Frequency Vibration

Microscale Capillary Wave Turbulence Excited by High Frequency Vibration

Silk films with nanotopography and extracellular proteins enhance corneal epithelial wound healing

Coupling light and sound: giant nonlinearities from oscillating bubbles and droplets

Contact Info

Product

Resources

About