MNRL

Apr 13

Precise drop dispensation [sic] on superhydrophobic surfaces using acoustic nebulization -

 

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From DOI: 10.1039/c3sm00016h

The adhesion forces of liquid drops on superhydrophobic surfaces are typically in the nano-Newton range which presents problems in their dispensation from pipettes. Furthermore, since the liquid adheres more strongly to the pipette tip, some portion of the…

Fast surface acoustic wave-matrix-assisted laser desorption ionization mass spectrometry [MALDI-MS] of cell response from islets of Langerhans -

 

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From DOI: 10.1021/ac3019125

A desire for higher speed and performance in molecular profiling analysis at a reduced cost is driving a trend in miniaturization and simplification of procedures. Here we report the use of a surface acoustic wave (SAW) atomizer for fast sample handling in…

Unique fingering instabilities and soliton-like wave propagation in thin acoustowetting films -

 

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From DOI: 10.1038/ncomms2168

Figure: (a) The setup with oil drop, (b) top view with fluorescence, (c) exposure to SAW draws a film toward the acoustic source, (d) the leading edge of the film deepens and forms rapidly moving drops away from the source, and (e) this develops into a…

Microscale Capillary Wave Turbulence Excited by High Frequency Vibration -

 

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From DOI: 10.1021/la304608a

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 due to the…

 

Polariton-based band gap and generation of surface acoustic waves in acoustic superlattice lithium niobate
We report the presence of surface acoustic wave (SAW, a) band gap (b) on acoustic superlattice (ASL) in a single-crystal lithium niobate structure. The calculated band gap appears at a frequency twice the value expected from purely acoustic Bragg scattering. We have identified the band gap as originating from a polariton-based mechanism due to the coupling between the electromagnetic wave and the surface vibrations. We have examined the influence of the band gap on SAW generation with the ASL and have shown that the (c) calculated frequency resonance of the SAW lies in the vicinity of the upper stop-band edges. This results in the localization of the SAW in the ASL. Experimental confirmation is achieved through direct measurement of the SAW displacement by laser vibrometry on an actual ASL SAW transducer. Paper is here, from the Journal of Applied Physics, and here from my web site.

 

Polariton-based band gap and generation of surface acoustic waves in acoustic superlattice lithium niobate

We report the presence of surface acoustic wave (SAW, a) band gap (b) on acoustic superlattice (ASL) in a single-crystal lithium niobate structure. The calculated band gap appears at a frequency twice the value expected from purely acoustic Bragg scattering. We have identified the band gap as originating from a polariton-based mechanism due to the coupling between the electromagnetic wave and the surface vibrations. We have examined the influence of the band gap on SAW generation with the ASL and have shown that the (c) calculated frequency resonance of the SAW lies in the vicinity of the upper stop-band edges. This results in the localization of the SAW in the ASL. Experimental confirmation is achieved through direct measurement of the SAW displacement by laser vibrometry on an actual ASL SAW transducer. Paper is here, from the Journal of Applied Physics, and here from my web site.

Hydroxypropyl cellulose methacrylate as a photo-patternable and biodegradable hybrid paper substrate for cell culture and other bioapplications -

 

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From here at Advanced Healthcare Materials.

In addition to the choice of appropriate material properties of the tissue construct to be used, such as its biocompatibility, biodegradability, cytocompatibility, and mechanical rigidity, the ability to incorporate microarchitectural patterns…

 

Continuous flow actuation between external reservoirs in small-scale devices driven by surface acoustic waves
From here at RSC Lab-on-a-Chip:
We have designed and characterized a surface acoustic wave (SAW) fluid actuation platform that significantly improves the transmission of sound energy from the SAW device into the fluid in order to obtain enhanced performance. This is in distinct contrast to previous SAW microfluidic devices where the SAW substrate is simply interfaced with a microchannel without due consideration given to the direction at which the sound energy is transmitted into the fluid, thus resulting in considerable reflective and dissipative losses due to reflection and absorption at the channel walls. For the first time, we therefore demonstrate the ability for continuous fluid transfer between independent reservoirs driven by the SAW in a miniature device, and report the associated pressure–flow rate relationship, in which a maximum flowrate of 100 μl/min and pressure of 15 Pa was obtained. The pumping efficiency is observed to increase with input power, and, at peak performance, offers an order-of-magnitude improvement over that of existing SAW micropumps that have been reported to date. Paper here.

 

Continuous flow actuation between external reservoirs in small-scale devices driven by surface acoustic waves

From here at RSC Lab-on-a-Chip:

We have designed and characterized a surface acoustic wave (SAW) fluid actuation platform that significantly improves the transmission of sound energy from the SAW device into the fluid in order to obtain enhanced performance. This is in distinct contrast to previous SAW microfluidic devices where the SAW substrate is simply interfaced with a microchannel without due consideration given to the direction at which the sound energy is transmitted into the fluid, thus resulting in considerable reflective and dissipative losses due to reflection and absorption at the channel walls. For the first time, we therefore demonstrate the ability for continuous fluid transfer between independent reservoirs driven by the SAW in a miniature device, and report the associated pressure–flow rate relationship, in which a maximum flowrate of 100 μl/min and pressure of 15 Pa was obtained. The pumping efficiency is observed to increase with input power, and, at peak performance, offers an order-of-magnitude improvement over that of existing SAW micropumps that have been reported to date. Paper here.

[video]

 

Ultraviolet laser-induced domain inversion on chromium-coated lithium niobate crystals
From here at Optics Express.
Direct UV laser writing on chromium coated lithium niobate (LiNbO3) crystals is found to produce spontaneous domain inversion associated with the exposed UV laser tracks. Experimental evidence suggests that this effect is attributed to local out-diffusion of oxygen, reducing the LiNbO3 crystal surface due to the presence of chromium. The thin chromium film becomes hot and reactive after absorbing the UV laser radiation thus acting as an oxygen getter. This very efficient process enables the inversion of domains at lower intensities as compared to other direct laser based poling methods practically eliminating the deleterious surface damage induced by the direct absorption of the UV laser radiation by the crystal. Furthermore, the versatility of this domain fabrication method, is demonstrated by the production of inverted domain structures on Z-, Y- and 128 deg YX-cut substrates. Paper here.

 

Ultraviolet laser-induced domain inversion on chromium-coated lithium niobate crystals

From here at Optics Express.

Direct UV laser writing on chromium coated lithium niobate (LiNbO3) crystals is found to produce spontaneous domain inversion associated with the exposed UV laser tracks. Experimental evidence suggests that this effect is attributed to local out-diffusion of oxygen, reducing the LiNbO3 crystal surface due to the presence of chromium. The thin chromium film becomes hot and reactive after absorbing the UV laser radiation thus acting as an oxygen getter. This very efficient process enables the inversion of domains at lower intensities as compared to other direct laser based poling methods practically eliminating the deleterious surface damage induced by the direct absorption of the UV laser radiation by the crystal. Furthermore, the versatility of this domain fabrication method, is demonstrated by the production of inverted domain structures on Z-, Y- and 128 deg YX-cut substrates. Paper here.

 

Controlled morphogenesis and self-assembly of bismutite nanocrystals into three-dimensional nanostructures and their applications
From here at Journal of Materials Chemistry A, showing the complex micro/nanostructure formed by Na3C6H5O7 at different pH values.
It is now possible to control the morphogenesis and self-assembly of bismutite nanocrystals with fully tunable morphologies from square plates, octagonal sheets, and round disks into three-dimensional hierarchical nanostructures. The results show that the nucleation, growth and self-assembly of bismutite nanocrystals strongly depend on the synergistic effect between hydroxide and citrate ions. The three-dimensional hierarchical nanostructures are formed through an oriented-attachment of bismutite nanocrystals along the 〈001〉 directions. The bismutite hierarchical nanostructures can be utilized for efficient and selective adsorption and separation. A novel surface-enhanced Raman spectroscopy platform based on a bismutite/gold nanoparticles core–shell structure has been developed for ultrasensitive detection of aromatic molecules with a detection limit down to 1 nM. Paper here.

 

Controlled morphogenesis and self-assembly of bismutite nanocrystals into three-dimensional nanostructures and their applications

From here at Journal of Materials Chemistry A, showing the complex micro/nanostructure formed by Na3C6H5O7 at different pH values.

It is now possible to control the morphogenesis and self-assembly of bismutite nanocrystals with fully tunable morphologies from square plates, octagonal sheets, and round disks into three-dimensional hierarchical nanostructures. The results show that the nucleation, growth and self-assembly of bismutite nanocrystals strongly depend on the synergistic effect between hydroxide and citrate ions. The three-dimensional hierarchical nanostructures are formed through an oriented-attachment of bismutite nanocrystals along the 〈001〉 directions. The bismutite hierarchical nanostructures can be utilized for efficient and selective adsorption and separation. A novel surface-enhanced Raman spectroscopy platform based on a bismutite/gold nanoparticles core–shell structure has been developed for ultrasensitive detection of aromatic molecules with a detection limit down to 1 nM. Paper here.