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Innovation Grants Program

Fluidic Manipulation in Carbon Nanotubes

Jennifer R. Lukes
William K. Gemmill Assistant Professor
Department of Mechanical Engineering and Applied Mechanics
University of Pennsylvania, Philadelphia, PA

Directed transport of confined fluidsNanofluidic control of minute quantities of liquid has tremendous implications for biotechnology and biochemical analysis, with a wide array of potential applications including drug discovery, targeted deposition of optical probes, and manipulation of entrained particles and macromolecules. Although considerable progress has been made recently in the ability to pump and experimentally observe fluids at the nanoscale, much is still not understood about transport in nanochannels, where noncontinuum behavior such as pulsatile fluidic transport, dramatically increased effective viscosity, and ‘stick-slip’ flow emerge. The objective of this project is to obtain a fundamental understanding of the influence of external fields on the transport of confined fluids. Specifically, atomistic molecular dynamics simulations (Fig. 1) are being used to model the transport of polarizable and charged fluids through carbon nanotubes as a function of concentration, temperature, surface charge, and electric field. This work will provide information useful for the design of innovative new mechanisms for nanoscale pumping and control.


 

Exploration of Nanorod-based Structures and Their Optoelectronic Devices

Marija Drndic
Assistant Professor of Physics and Astronomy
University of Pennsylvania, Philadelphia, PA

Controlled manipulation and assembly of nanorods and other kinds of nanocrystals (nanometer-size crystals with small numbers of atoms) are crucial for the study and realization of novel optoelectronic devices with unique and surprising properties. Using recent advances in synthetic chemistry, we can make semiconductor nanorods to study their assembly patterns and to discover the basic mechanisms behind the charge transport inside of sub-micron devices.

Transmission electron micrographs of CdSe (cadmium selenide) nanorods Fig.1: Transmission electron micrographs of CdSe (cadmium selenide) nanorods dispersed on substrates from solutions. Nanorods in these images have an aspect ratio (length:width) of about 4. They are about 20 nm long and about 5 nm wide. Image (a) is for a low concentration, while image (b) is for a high concentration of nanorods.

Generating electrospun nanofibers

Jorge J. Santiago-Aviles
Associate Professor of Electrical Engineering
Moore School of Electrical Engineering
University of Pennsylvania, Philadelphia, PA

electro-statically deposited (electrospun) nanoscopic electronicProf. Santiago-Avilés works with electro-statically deposited (electrospun) nanoscopic electronic materials. Our group work involves the generation of nano-fibers of electrically and thermally conductive carbon (graphitic) from polymeric precursors, semiconductive tin oxide and piezo / ferroelectric lead zirconate titanate (PZT) from organometallic precursors. Grain growth and charge carrier transport confinement in a quasi-one dimensional structure such as the nanofibers have lead to novel science and interesting possibilities in terms of applications.


 

Nanowire-Enabled Scanning Probes: Tools for Investigating Protein Interactions

Jonathan E Spanier
Assistant Professor
Materials Science & Engineering, and
Drexel Nanotechnology Institute, Drexel University, Philadelphia PA

 

single-crystalline Si nanocone
High-resolution transmission electron microscopy image of a representative, individual, single-crystalline Si nanocone with tip radius of curvature of ~1-2 nm as grown at Drexel. Upper inset: selected area electron diffraction pattern from this nanocone, demonstrating single-crystalline structure. Lower inset: scanning electron microscopy (SEM) image of a cluster of nanocones; the length scale in the SEM image is 5 mm.

Inorganic, single-crystalline nanowires possess unique combinations of properties; their application in devices has enabled important advances in the state-of-the-art in nanoelectronics, nanophotonics, and in the sensing of individual biomolecules. At the same time, experimental methods employing functionalized single-walled or multi-walled carbon nanotubes as scanning probes have extended imaging techniques to provide chemical force microscopy of biomolecules on surfaces with specificity and unprecedentedly high lateral spatial resolution. However, some sensing and imaging modalities for investigating protein interactions on surfaces and for other extracellular probing may benefit from the additional flexibility in the selection of composition, surface chemistry, topology, diameter, conductivity, mechanical properties and function of semiconducting and other inorganic nanowires as scanning probes. We are currently (a) investigating nanostructure growth modes that allow formation of single and multi-component one-dimensional inorganic nanostructures on a variety of platforms, including some nanostructures with novel topographies (see figure), and (b) developing new scanning probe strategies involving these nanostructures that will complement and enhance present methods for quantitative detection and imaging of protein binding and interaction events.

 

Nano/Bio Interface Center @ The University of Pennsylvania
info@nanotech.upenn.edu
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