Pang Hua-Feng

Xi'an University of Science and Technology · Department of Applied Physics

Extensive attention has recently been paid to the advances in smart piezoelectric films for sensors and actuators applications because of their unique advantages, including high performance, easy integration with CMOS electronics, and diversity and flexibility of the device designs. in this chapter, the fundamental aspects of smart piezoelectric fi...

Transparent microfluidic devices based on ZnO thin film/glass surface acoustic waves (SAWs) were explored for active surface cleaning based on its acoustofluidic performance. Acoustic waves generated from ZnO films on glass substrate were investigated and their acoustofluidic performance including transportation, jetting and nebulization were evalu...

There are significant challenges in controlling uniformity of crystal inclination angles, growth orientations and film thicknesses to generate dual-mode surface acoustic waves (e.g., Rayleigh ones and shear-horizontal ones) for lab-on-a-chip applications. In this study, we demonstrate large area (up to three inches) and uniformly inclined piezoelec...

Different acoustic wave modes are required for effective implementation of biosensing and liquid actuation functions in an acoustic wave-based lab-on-a-chip. For efficient sensing in liquids, shear waves (either a thickness shear bulk wave or shear-horizontal surface acoustic wave) can achieve a high sensitivity, without significant loss of acousti...

Progress in ZnO thin films and nanostructures for the acoustic wave micro- fluidic and sensing applications are reviewed in this chapter. ZnO thin films with good piezoelectric properties possess large electromechanical coupling coefficients and can be fabricated for the surface acoustic wave (SAW) and film-bulk acoustic resonator (FBAR) devices wi...

Erbium-doped lead tungstate (PbWO4) microcrystals with different doping concentrations have been synthesized using an aqueous precipitation method under the assistance of cetyltrimethyl ammonium bromide (CTAB). The results characterized by X-ray diffraction and scanning electron microscope show that the tetragonal stolzite microcrystals with a spin...

Progress in ZnO thin films and nanostructures for the acoustic wave micro- fluidic and sensing applications are reviewed in this chapter. ZnO thin films with good piezoelectric properties possess large electromechanical coupling coefficients and can be fabricated for the surface acoustic wave (SAW) and film-bulk acoustic resonator (FBAR) devices wi...

In this study, the nonresonant two-photon absorption process in a two-level atom, induced by a weak chirped pulse, is theoretically investigated in the frequency domain. An analytical expression of the wave function expressed by Fresnel functions is obtained, and the two-photon transition probability (TPTP) versus the integral bandwidth, spectral w...

We have prepared an electron-doped manganite La0.9Hf0.1MnO3 (LHMO) by a solid state reaction method, and then systematically investigated its structural, magnetic and magnetocaloric properties. The analysis of XRD data based on Rietveld refinement reveals that the LHMO sample crystallizes in the rhombohedral structure with a space group of RC. M(T)...

Shear horizontal surface acoustic waves (SH-SAWs) have been regarded as good candidates for liquid sensing applications but are inefficient in fluid manipulation due to a minimal fluid coupling between the fluid and acoustic waves. However, in this letter, a vertical jetting function was realized using the SH-SAW generated from a 36° Y-X LiTaO3SAW...

Nanostructured indium oxide (In2O3) microcrystals were prepared by calcining hydrothermally synthesized indium hydroxide (In(OH)3) samples. A cubic structure and small crystallite sizes of the In2O3 microcrystals are determined from the X-ray diffraction (XRD) analysis. Observation of the scanning electron microscopy (SEM) shows that the crystallin...

Nanocrystalline ZnO films with strong (0002) texture and fine grains were deposited onto ultra-nanocrystalline diamond (UNCD) layers on silicon using high target utilization sputtering technology. The unique characteristic of this sputtering technique allows room temperature growth of smooth ZnO films with a low roughness and low stress at high gro...

Droplet streaming and nebulization on a shear horizontal surface acoustic wave device made of 36o Y-cut LiTaO3 have been reported. The streaming pattern inside the droplet is sensitive to the droplet shape, the position to the interdigital transducer, and the aperture size. Droplet nebulization was enhanced with the increased aperture size of the d...

Ultra-smooth nanocrystalline diamond (UNCD) films with high-acoustic wave velocity were introduced into ZnO-based surface acoustic wave (SAW) devices to enhance their microfluidic efficiency by reducing the acoustic energy dissipation into the silicon substrate and improving the acoustic properties of the SAW devices. Microfluidic efficiency of the...

Hierarchical structured tungsten oxide nanocrystals were synthesized via the hydrothermal route assisted by a capping agent of ammonium benzoate (AB). The products were characterized using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. The experimental results show that the c...

Surface acoustic wave (SAW) devices with 64 μm wavelength were fabricated on a zinc oxide (ZnO) film deposited on top of an ultra-smooth nanocrystalline diamond (UNCD) layer. The smooth surface of the UNCD film allowed the growth of the ZnO film with excellent c-axis orientation and low surface roughness, suitable for SAW fabrication, and could res...

Crystals of hexagonal tungsten oxides (hex-WO3) have been synthesized using hydrothermal method at 150 °C, assisted by the capping reagent of ammonium tartrate (AT). The XRD and EDX results reveal that the lattice distortion exists in all the samples, possibly due to the defects and the intercalation of the residual sodium ions. Different crystal s...

Shuttle-like lead tungstate (PbWO4) microcrystals are synthesized at room temperature using the precipitation method with the cetyltrimethyl ammonium bromide. Results from both the X-ray diffraction and the scanning electron microscopy show that the lattice distortions of the PbWO4 microcrystals are reduced significantly when the annealing temperat...