Characterization of Outer Insulation in Long-Term-Implanted Leads.

Success of pacemakers and implantable cardioverter defibrillators may be limited by premature lead failure. Lead insulation polymers, such as polyurethane (PU) and polydimethylsiloxane (PDMS), are reported to degrade over time in vivo. PU is known to undergo oxidation, whereas PDMS undergoes surface hydrolysis.

Effects of gamma and e-beam sterilization on the chemical, mechanical and tribological properties of a novel hydrogel.

Hydrogels are known to possess cartilage-like mechanical and lubrication properties; however, hydrogel sterilization is challenging. Cyborgel(™), a proprietary hydrogel, is intended for use as a cartilage replacement implant. This study evaluated the effect of 30-35 kGy e-beam and gamma radiation on the polymer swell ratio, and the mechanical, chemical and tribological behavior of this hydrogel.

Percolating bulk heterostructures from neutron reflectometry and small-angle scattering data.

We generate percolating fullerene-polymer bulk heterostructures that are consistent with the experimental characterization of a nanostructure, in particular neutron reflectometry and small-angle neutron scattering data from as-cast and annealed poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester systems. Transport simulations correlate changes in exciton dissociation efficiency and charge collection efficiency with morphological features including characteristic domain size, fullerene concentration profile, degree of fullerene sequestration, and degree of P3HT crystallization.