281,483 research outputs found
Current approaches for modulation of the nanoscale interface in the regulation of cell behavior
Regulation of cell behavior in response to nanoscale features has been the focus of much research in recent years and the successful generation of nanoscale features capable of mimicking the natural nanoscale interface has been of great interest in the field of biomaterials research. In this review, we discuss relevant nanofabrication techniques and how they are combined with bioengineering applications to mimic the natural extracellular matrix (ECM) and create valuable nanoscale interfaces
Nanoscale ear drum: Graphene based nanoscale sensors
The difficulty in determining the mass of a sample increases as its size
diminishes. At the nanoscale, there are no direct methods for resolving the
mass of single molecules or nanoparticles and so more sophisticated approaches
based on electromechanical phenomena are required. More importantly, one
demands that such nanoelectromechanical techniques could provide not only
information about the mass of the target molecules but also about their
geometrical properties. In this sense, we report a theoretical study that
illustrates in detail how graphene membranes can operate as
nanoelectromechanical mass-sensor devices. Wide graphene sheets were exposed to
different types and amounts of molecules and molecular dynamic simulations were
employed to treat these doping processes statistically. We demonstrate that the
mass variation effect and information about the graphene-molecule interactions
can be inferred through dynamical response functions. Our results confirm the
potential use of graphene as mass detector devices with remarkable precision in
estimating variations in mass at molecular scale and other physical properties
of the dopants
Nanoscale magnetophotonics
This Perspective surveys the state-of-the-art and future prospects of science
and technology employing the nanoconfined light (nanophotonics and
nanoplasmonics) in combination with magnetism. We denote this field broadly as
nanoscale magnetophotonics. We include a general introduction to the field and
describe the emerging magneto-optical effects in magnetoplasmonic and
magnetophotonic nanostructures supporting localized and propagating plasmons.
Special attention is given to magnetoplasmonic crystals with transverse
magnetization and the associated nanophotonic non-reciprocal effects, and to
magneto-optical effects in periodic arrays of nanostructures. We give also an
overview of the applications of these systems in biological and chemical
sensing, as well as in light polarization and phase control. We further review
the area of nonlinear magnetophotonics, the semiconductor spin-plasmonics, and
the general principles and applications of opto-magnetism and nano-optical
ultrafast control of magnetism and spintronics
Nanoscale capacitance: a classical charge-dipole approximation
Modeling nanoscale capacitance presents particular challenge because of
dynamic contribution from electrodes, which can usually be neglected in
modeling macroscopic capacitance and nanoscale conductance. We present a model
to calculate capacitances of nano-gap configurations and define effective
capacitances of nanoscale structures. The model is implemented by using a
classical atomic charge-dipole approximation and applied to calculate
capacitance of a carbon nanotube nano-gap and effective capacitance of a
buckyball inside the nano-gap. Our results show that capacitance of the carbon
nanotube nano-gap increases with length of electrodes which demonstrates the
important roles played by the electrodes in dynamic properties of nanoscale
circuits.Comment: 11 pages, 6 figure
Dynamics at the nanoscale
However fascinating structures may be at the nanoscale, time-dependent behaviour at the nanoscale has far greater importance. Some of the dynamics is random, with fluctuations controlling rate processes and making thermal ratchets possible. Some of the dynamics causes the transfer of energy, of signals, or of charge. Such transfers are especially efficiently controlled in biological systems. Other dynamical processes occur when we wish to control the nanoscale, e.g., to avoid local failures of gate dielectrics, or to manipulate structures by electronic excitation, to use spin manipulation in quantum information processing. Our prime purpose is to make clear the enormous range and variety of time-dependent nanoscale phenomena. (C) 2006 Elsevier B.V. All rights reserved
Charge transport in nanoscale vertical organic semiconductor pillar devices
We report charge transport measurements in nanoscale vertical pillar
structures incorporating ultrathin layers of the organic semiconductor
poly(3-hexylthiophene)(P3HT). P3HT layers with thickness down to 5 nm are
gently top-contacted using wedging transfer, yielding highly reproducible,
robust nanoscale junctions carrying high current densities (up to
A/m). Current-voltage data modeling demonstrates excellent hole injection.
This work opens up the pathway towards nanoscale, ultrashort-channel organic
transistors for high-frequency and high-current-density operation.Comment: 30 pages, 8 figures, 1 tabl
Polarization aspects of near-field radiation from nanoscale subwavelength apertures
It is demonstrated that a square nanoaperture can mediate polarized diffractionlimited radiation into nanoscale optical spots with the same polarization. A rectangular nanoaperture can convert linearly-polarized diffraction-limited radiation into circularly and elliptically-polarized nanoscale optical spots
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