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Research Image

@Research !

  • Postdoctoral Research:

---- Will come soon--

  • Ph. D :

Dewetting describes the rupture of a thin liquid film on the substrate (either a liquid itself, or a solid) and the formation of droplets.It is likely that we all have observed that water forms droplets on various surfaces, such as naturally occurring biosystems like leaves. The underlying reason for the formation of drops is that the droplet–surface system has lower energy than the film–substrate system, hence water dewets and forms droplets on leaves. The phenomenon of dewetting has important implications in industry ,biology and chemical sensing.Taking a cue from the natural systems, our Lab (Group for Nano and Thin Film Sciences @UTK) works on materials assembly methods, based on nanofabrication, where a very simple input geometry (a thin metal film ) was deposited to produce a more complex output (a precise, array of nanoparticles/nanocomposites) using pulsed laser irradiation.The metallic nanoparticle/nanocomposite arrays prepared by pulsed laser induced dewetting in thin metallic films have the potential for applications in biosensing, biocatalysis, high-density magneto-optical technologies, and in electronic materials with photon and spin-dependent electronic behavior.

My research at Prof.Ramki's Lab is focussed on:

  • To utilize pulsed laser dewetting technique of ultrathin metal films (~ 2 nm to 20 nm) to synthesize nanostructures on surfaces.
  • To understand the role of physical mechanisms like mass & thermal transport in dewetting of single layer (Au or Ag/ Substrate) and bilayer films (AuCo or AgNi /Substrate).
  • To overcome the current limitations in dewetting & explore novel ways to fabricate metallic nano-strucures on surfaces.
  • Collaborate with other research groups to investigate the role of size & spacing of metal nanostructures on plasmonics, chemical sensing via SERS & energy harvesting.

Dewetting

Figure : (a) Dewetting of water on a leaf. (b) Deposition of metallic thin films in UHV chamber using PVD techniques. (Image courtesy : Prof. Ramki) (c) Dewetting of silver 10nm film using pulsed laser irradiation. (d) Chemical sensing via SERS.

 

Tools used for Research:

  • Synthesis:
    • Ultra high vacuum chamber (UHV)
    • E-beam evaporation
    • Pulsed laser (266 nm, 50 Hz)
    • Soft lithography
    • Laser micromachining
  • Characterization:
    • Atomic force microscope (AFM)
    • Magnetic force microscope (MFM)
    • Scanning electron microscope (SEM)
    • Energy dispersive X-ray scattering (EDS)
    • Surface magneto optic kerr analysis (SMOKE)
    • UV-Vis spectroscopy
    • Confocal Raman Microscopy
    • Transmission Electron Microscope (TEM)
    • Profilometer
  • Analysis:
    • Image J
    • Gwyddion
    • Matlab
    • Comsol multiphysics
    • Draft sight