Nebulisation on a disposable array structured with phononic lattices

Abstract

We demonstrate the use of a phononic crystal to enable the nebulisation of liquid droplets from low-cost disposable arrays, using surface acoustic waves (SAW). The SAWs were generated using interdigitated transducers (IDT) on a piezoelectric surface (LiNbO(3)) and the acoustic waves were coupled into a disposable phononic crystal structure, referred to as a superstrate. Using its excellent reflecting properties, the phononic structures confined the acoustic field within the superstrate, resulting in the concentration of the acoustic energy, in a manner controllable by the excitation frequency. We show that this capability mitigates against coupling losses incurred by the use of a disposable superstrate, greatly reducing the time needed to nebulise a drop of water with respect to an unstructured superstrate for a given power. We also demonstrate that by changing the excitation frequency, it is possible to change the spatial position at which the acoustic energy is concentrated, providing a means to specifically nebulise drops across an array. These results open up a promising future for the use of phonofluidics in high-throughput sample handling applications, such as drug delivery or the "soft" transfer of samples to a mass spectrometer in the field of proteomics.

Surface acoustic wave nebulization on nanocrystalline ZnO film

“…1,2,7-9 Among these streaming phenomena, surface acoustic wave nebulization (SAWN) has been studied extensively due to its wide potential applications in targeted drug delivery, patterning of nanoparticles, cell or protein generation, inhalation therapy, mass spectrometric analysis, deposition of biochemical films, etc. [9][10][11][12][13][14][15][16] Recently, there has been an increasing interest in SAW based microfluidic devices using high performance piezoelectric thin film materials, such as ZnO. [17][18][19][20][21] These ZnO films, typically a few micron thick, deposited on silicon, glass, or polymer, have advantages compared with using bulk materials such as LiNbO 3 or quartz.…”

Future Prospects of Phononic Crystals and Phononic Metamaterials

“…By their natural frequency selective characteristics and guiding capabilities they can play a major role in developing lab on chip applications. Reboud et al have demonstrated the capability of phononic crystal structures in handling liquids [16][17][18]. Various functions such as microcentrifugation of particles and blood cells and selective nebulization of liquid micro-droplets have been demonstrated to be very effective using phononic crystal structures.…”

Confinement of surface waves at the air-water interface to control aerosol size and dispersity

“…1 These waves can couple into thin plates, placed on the piezoelectric material, where they propagate as Lamb waves. 2 When a liquid is placed in the propagation path of such waves, on a thin plate, the ultrasonic wave refracts into the fluid with a transfer of mechanical energy and radiative pressure that leads to fluid streaming, Fig. 1.…”