Tunable Nanowire Patterning Using Standing Surface Acoustic Waves.

ACS Nano (Impact Factor: 12.03). 03/2013; DOI: 10.1021/nn4000034
Source: PubMed

ABSTRACT Patterning of nanowires in a controllable, tunable manner is important for the fabrication of functional nanodevices. Here we present a simple approach for tunable nanowire patterning using standing surface acoustic waves (SSAW). This technique allows for the construction of large-scale nanowire arrays with well-controlled patterning geometry and spacing within 5 seconds. In this approach, SSAWs were generated by interdigital transducers (IDTs), which induced a periodic alternating current (AC) electric field on the piezoelectric substrate and consequently patterned metallic nanowires in suspension. The patterns could be deposited onto the substrate after the liquid evaporated. By controlling the distribution of the SSAW field, metallic nanowires were assembled into different patterns including parallel and perpendicular arrays. The spacing of the nanowire arrays could be tuned by controlling the frequency of the surface acoustic waves. Additionally, we observed 3D spark-shape nanowire patterns in the SSAW field. The SSAW-based nanowire-patterning technique presented here possesses several advantages over alternative patterning approaches, including high versatility, tunability, and efficiency, making it promising for device applications.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The surface enhanced Raman scattering effect has shown immense potential for detecting trace amounts of explosive vapor molecules. To date, efforts to produce a commercially available, reliable SERS sensor have been impeded by an inability to separate the electromagnetic enhancement produced by the metallic nanostructure from other signal enhancing effects. Here, we show a new Raman sensor that uses surface acoustic waves (SAWs) to produce controllable surface structures on gold films deposited on LiNbO3 substrates that modulate the Raman signal of a target compound (thiophenol) adsorbed on the films. We demonstrate that this sensor can dynamically control the Raman signal simply by changing the SAW’s amplitude, allowing the Raman signal enhancement factor to be directly measured with no variation in the concentration of the target compound. The physically adsorbed molecules can be removed from the sensor without physical cleaning or damage, making it possible to reuse it for real-time Raman detection.
    Journal of Raman Spectroscopy 06/2014; 45(8):636-641. · 2.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Self-assembly of nanowires into micro-scale patterns, especially those with controlled manners, has aroused increasing research interests because of their wide variety of potential applications including micro-optics and electronics devices, as well as the nanomaterials-based energy conversion systems. In this contribution, a novel laser-assisted solution spreading method was developed to fabricate and self-assembly alumina nanowires (ANWs) into large-scale 3-dimensional (3-D) micro-patterned surface in one-step. Here, sodium hydroxide (NaOH) solution played a dual role simultaneously with one is chemically etching of anodic aluminum oxide template (AAO) into ANWs and the other is self-assembling the as-obtained ANWs into micro-patterns under the capillary force. To be noticed, the micro-scale patterns can be artificially controlled by introducing laser points before solution spreading on the AAO template, and thus the laser-etched area will act as the fixation points during ANWs assembling process. Moreover, the as-prepared micro-patterned ANWs film exhibits the typical micro-/nano- hierarchical surface topology and shows superhydrophilicity, which can be turned into a superhydrophobic surface by chemical modification of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FAS). Here, by taking the advantage of wetting and dewetting process of solution on an AAO template, we propose a facile method that enables fabricating the 3D micro-patterned ANWs surfaces, which gives superwetting property. We envision this method could shed new light on the fabrication functional micro-patterned devices where one-dimensional nano-material and solution phase are involved.
    CrystEngComm 08/2014; · 3.86 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Precise reconstruction of heterotypic cell-cell interactions in vitro requires the coculture of different cell types in a highly controlled manner. In this article, we report a standing surface acoustic wave (SSAW)-based cell coculture platform. In our approach, different types of cells are patterned sequentially in the SSAW field to form an organized cell coculture. To validate our platform, we demonstrate a coculture of epithelial cancer cells and endothelial cells. Real-time monitoring of cell migration dynamics reveals increased cancer cell mobility when cancer cells are cocultured with endothelial cells. Our SSAW-based cell coculture platform has the advantages of contactless cell manipulation, high biocompatibility, high controllability, simplicity, and minimal interference of the cellular microenvironment. The SSAW technique demonstrated here can be a valuable analytical tool for various biological studies involving heterotypic cell-cell interactions.
    Analytical Chemistry 09/2014; · 5.83 Impact Factor


Available from
May 27, 2014