May News from Center for Nanoscale Systems

The Nanowire May 2009

CNS is an open, shared-use laboratory serving R&D professionals in New England and beyond, specializing in cleanroom fabrication, imaging, and materials synthesis and characterization. Academic, non-academic, and industrial partner programs available.

Upcoming CNS Events

Tuesday May 12, 2009
2:30 pm
"Controlling Light with Nano-Optics"

Prof. Srinivas Sridhar
Northeastern University
LISE 303
Controlling the speed of light, in addition to the direction, is a fundamental challenge that can lead to new physical phenomena and applications. We have proposed new concepts to stop and trap light pulses that utilize anomalous wave propagation in waveguides in semiconductor heterostructures with negative index metamaterial core or cladding. These metamaterial waveguides offer the prospect of on-chip slow light devices where light speeds are reduced by orders of magnitude, enabling ultra-compact optical delay lines and buffers.
These negative index metamaterials and devices offer the prospect of revolutionary developments in imaging and optoelectronics.

Thursday May 14, 2009 11:00 am
"High Charge Sensitivity With a Quantum Dot As a Charge Sensor: Experimental, Numerical and Theoretical Results"

Morten Kjærgaard, Neils Bohr Institute
LISE 303
We simulate the experimental device by performing self-consistent electronic structure calculations of the device, in the effective mass, local density approximation to density functional theory. A master equation is employed to compute the conductance through the Coulomb blockaded SQD and a simple WKB approximation is used with the evolving QPC potential profile to determine the conductance through the QPC. The numerical results, which substantially agree with experiment, are explained with an heuristic model of screening in the two systems (i.e. QPC and SQD). We show that the polarizability of the open QPC system screens either the gate or the effective gate (represented by the double dot charge state) and therefore significantly reduces the influence of the external potential. By contrast, the Coulomb blockaded SQD possesses a gap at the Fermi surface and its polarizability is consequently much reduced. A simple model employing capacitances is introduced to elucidate the physics.

Monday June 1, 2009
Helium Ion Microscopy: a new tool in the bio-/nanoscience toolkit

Dr. Daniel Pickard, National University of Singapore
LISE 303
The Helium Ion Microscope (HIM) is a new imaging technology based on high brightness and stable Gas Field Ion Source (GFIS). We have applied this novel technology across a broad spectrum of multidisciplinary applications to assess its utility and advantages over alternative techniques. One area where our investigations have gained significant traction is in the imaging of biological specimens. The utility of this instrument in addressing topics of the biological sciences is due in part to the HIM's high spatial resolution. However, in the context of biological specimens, it is the ability to image non-conductive samples without the application of a metal (or other conductive) overcoat and without the need of a background gas (both of which degrade resolution and surface details) which has proven to be a distinguishing attribute. In terms of scientific problems that are being investigated, we have initiated studies in cellular biomechanics where we are exploring the detailed organization of the actin cytoskeleton in cell motility, in bacterial pathogenesis where we are studying the bacterial invasion of epithelial cells and how the bacteria bind to the epithelial cells in the invasion process, and in health effects on engineered nanoparticles where we are tracking the transportation and aggregation/disaggregation of nanoparticles within exposed rodents.

June 24-26, 2009
Sixth Annual CARS Workshop

Coherent Raman Scattering (CRS) microscopy allows noninvasive 3D imaging of live cells based on the vibrational contrast intrinsic to a cell's molecular species. Through improvements in detection sensitivity, theoretical understanding of the contrast mechanism, and development of new laser sources, CRS microscopy, including coherent anti-Stokes Raman scattering (CARS) and Stimulated Raman Scattering (SRS) microscopies have matured as powerful methodologies for bio-imaging. This training course will reflect the state-of-the-art of these rapidly evolving techniques, providing understanding of the underlying principles of nonlinear coherent microscopy, and hands-on experience with CRS in tandem with confocal microscopy.
CARS Workshop 2009

Other Upcoming Events

May 27-29, 2009
Nanomanufacturing Summit 2009

Sheraton Boston Hotel
The Nanomanufacturing Summit 2009 is a showcase for high-quality technical contributions by experts and practitioners in the field of nanomanufacturing, as well as a networking event for the broader nanomanufacturing (NM) community. A primary objective is to highlight those areas of practice that stand out from the general nanotechnology and nanoscience themes as being near-term and having the potential to facilitate the commercial development and/or marketable application of nanoscale systems and devices.
Summit 2009 Link