Biomedical subjects

Shekhar Subramoney

Publications and source records attributed to Shekhar Subramoney.

3 recordsLinked to original sources

PubMed2005

Inorganic oxide core, polymer shell nanocomposite as a high K gate dielectric for flexible electronics applications.

Organic/inorganic core shell nanoparticles have been synthesized using high K TiO(2) as the core nanoparticle, and polystyrene as the shell. This material is easy to process and forms transparent continuous thin films, which exhibit a dielectric constant enhancement of over 3 times that of bulk polystyrene. This new dielectric material has been incorporated into capacitors and thin film transistors (TFTs). Mobilities approaching 0.2 cm(2)/V.s have been measured for pentacene TFTs incorporating the new TiO(2) polystyrene nanostructured gate dielectric, indicating good surface properties for pentacene film growth. This novel strategy for generating high K flexible gate dielectrics will be of value in improving organic and flexible electronic device performance.

Electronics↗

PubMed2003

Peptides with selective affinity for carbon nanotubes.

Because of their extraordinary electronic and mechanical properties, carbon nanotubes have great potential as materials for applications ranging from molecular electronics to ultrasensitive biosensors. Biological molecules interacting with carbon nanotubes provide them with specific chemical handles that would make several of these applications possible. Here we use phage display to identify peptides with selective affinity for carbon nanotubes. Binding specificity has been confirmed by demonstrating direct attachment of nanotubes to phage and free peptides immobilized on microspheres. Consensus binding sequences show a motif rich in histidine and tryptophan, at specific locations. Our analysis of peptide conformations shows that the binding sequence is flexible and folds into a structure matching the geometry of carbon nanotubes. The hydrophobic structure of the peptide chains suggests that they act as symmetric detergents.

Microspheres↗

PubMedDate not supplied

Effect of interlayer potential on mechanical deformation of multiwalled carbon nanotubes.

A study on the modeling and simulation of interlayer interaction in the multiwalled carbon nanotube (MWCNT) system is presented. We use an interlayer Morse potential previously developed from a local density approximation (LDA) treatment of a bilayer of graphite. We have fit this Morse potential to experimental high-pressure compressibility data for graphite and to a more extensive LDA equation of state (EOS) for graphite, and excellent agreement is observed. We employ this potential to treat the interlayer mechanics of MWCNTs, where the MWCNT is so highly deformed that interlayer separation well below approximately 0.34 nm, such as down to approximately 0.26 nm, is occurring. This, to our knowledge, is the first treatment that attempts to account for deformations that have the layers approaching each other at very high local (interlayer) stress levels. Since evaluating the interlayer potential for a large MWCNT system is computationally intensive, a continuum simulation approach is proposed that saves on computational time and thus on cost. Comparisons with experimental results of buckled and highly kinked MWCNTs are presented.

Computer Simulation↗