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Polymer Nanosctructures

Polymer Nanosctructures
Fabrication of polymer nano-structures with stimuli responsive characteristics

Near Field Optical Imaging

Near Field Optical Imaging
Fully optical pump-probe technique to characterize the temporal/frequency response of excess charge carriers in semiconductors

Whispering Gallery Acoustic SPM

Whispering Gallery Acoustic SPM
Acoustic characterization of striking properties (higher viscosity, longer time response), different than the bulk, of mesoscopic fluid-like films confined between two sliding surfaces.
Welcome to the Nanophysics Research Group Webpage!

Our interest focuses on the characterization of dynamic processes occurring in materials of mesoscopic dimensions. They include  optical excitation and quantum conductance of charge carriers in semiconductors; acoustic monitoring of shear-interactions in confined fluid films under shear, and the pattern formation in stimuli-responsive polymers).

In the process of undertaking these studies we have developed new techniques:
       i)  High-resolution optical and acoustic near-field imaging techniques (τ-NSOM, SANM, and  WGAS),
       ii) Fabrication of nanostructures using polymers that have stimuli responsive properties (PEN),
      iii) Synthesis of copper nanowires, aiming to study quantum conductance in  mesoscopic systems.

These efforts have a multidisciplinary character undertaken in collaboration with Dr. Mingdi Yan, Dr. R. Nordstrom, and Dr. S. Rananavare.

The first group of these techniques i)  are implemented in a near-field modality in order to achieve higher lateral resolution (and thus overcome the diffraction limited resolution that hampers  conventional optical and acoustic techniques). The τ-NSOM allows mapping carrier lifetime in semiconductor materials with high lateral resolution. The high sensitivity of the Whispering Acoustic Sensing (WGAS) method has allowed us to implement a scanning probe microscope fully operated by acoustic feedback control. Further, our SANM has capability to listen the whispering of shear-force interactions, while characterizing the dynamics of mesoscopic films trapped between two sliding surfaces. The tandem WGAS and SANM bring another dimension for characterizing mesoscopic fluid films.

The multidisciplinary character of our research work has led us to develop, in collaboration with Dr. Mingdi Yan (at the University of Massachusetts Lowell), the Proton-fountain Electric-field-assisted Nanolithography (PEN) technique, which capitalizes on the estimuli responsive properties of polymers materials to create reversible pattern of mesoscopic dimensions.

To study the electrical and thermal characteristics of mesoscopic system, we are collaborating with Dr. Shankar Rananavare in the fabrication of copper-oxide nanowires. Copper-oxide is considered as a potential field emitter, an efficient catalytic agent, as well as a good gas sensing material. Recently, much attention has been paid to the photo-physicochemical properties of Cu2O materials since it could be used as light absorbing layer for photovoltaic cells and photocatalyst for overall water splitting under visible light irradiation.

 

We are located in Science Building 1 Room 30.
PHONE: 503-725-8397