Injectable, Magnetically Orienting Electrospun Fiber Conduits for Neuron Guidance.

Magnetic electrospun fibers are of interest for minimally invasive biomaterial applications that also strive to provide cell guidance. Magnetic electrospun fibers can be injected and then magnetically positioned in situ, and the aligned fiber scaffolds provide consistent topographical guidance to cells. In this study, magnetically responsive aligned poly-l-lactic acid electrospun fiber scaffolds were developed and tested for neural applications.

Multifold Electrical Conductance Enhancements at Metal-Bismuth Telluride Interfaces Modified Using an Organosilane Monolayer.

Controlling electrical transport across metal-thermoelectric interfaces is key to realizing high efficiency devices for solid state refrigeration and waste-heat harvesting. We obtain up to 17-fold increases in electrical contact conductivity Σ by inserting a mercaptan-terminated organosilane monolayer at Cu-BiTe and Ni-BiTe interfaces, yielding similar Σ for both metals by offsetting an otherwise 7-fold difference. The Σ improvements are underpinned by silane-moiety-induced inhibition of Cu diffusion, promotion of high-conductivity interfacial nickel telluride formation, and mercaptan-induced reduction of BiTe surface oxides.

Microwave synthesis of branched silver nanowires and their use as fillers for high thermal conductivity polymer composites.

We report a rapid synthesis approach to obtain branched Ag nanowires by microwave-stimulated polyvinylpyrrolidone-directed polyol-reduction of silver nitrate. Microwave exposure results in micrometer-long nanowires passivated with polyvinylpyrrolidone. Cooling the reaction mixture by interrupting microwave exposure promotes nanocrystal nucleation at low-surfactant coverage sites.

Tailoring Electrical Transport Across Metal-Thermoelectric Interfaces Using a Nanomolecular Monolayer.

We report a 13-fold increase in electrical contact conductivity Σc upon introducing a 1,8-octanedithiol (ODT) monolayer at Cu-Bi2Te3 interfaces. In contrast introducing ODT at Ni-Bi2Te3 interfaces results in a 20% decrease in Σc. Rutherford backscattering spectrometry, X-ray diffraction and electron spectroscopy analyses indicate that metal-sulfur and sulfur-Bi2Te3 bonds at metal-Bi2Te3 interfaces inhibit chemical mixing, curtail metal-telluride formation, and suppress oxidation.