Toward High-Performance Piezoresistive Polymer Derived SiOC Ceramics through Masked Stereolithography 3D Printing with β-Silicon Carbide Nanopowder Reinforcement.

Enhancing the piezoresistivity of polymer-derived silicon oxycarbide ceramics (SiOC ) is of great interest in the advancement of highly sensitive pressure/load sensor technology for use in harsh and extreme working conditions. However, a facile, low cost, and scalable approach to fabricate highly piezoresistive SiOC below 1400 °C still remains a great challenge. Here, the fabrication and enhancement of piezoresistive properties of SiOC reinforced with β-SiC nanopowders (SiC ) through masked stereolithography-based 3D-printing and subsequent pyrolysis at 1100 °C are demonstrated.

MOF/MWCNT-Nanocomposite Manipulates High Selectivity to Gas via Different Adsorption Sites with Varying Electron Affinity: A Study in Methane Detection in Parts-per-Billion.

Metal-organic frameworks (MOFs) present specific adsorption sites with varying electron affinity which are uniquely conducive to selective gas sensing but are typically large-band-gap insulators. On the contrary, multiwall carbon nanotubes (MWCNTs) exhibit superior mesoscopic transport exploiting strong electron correlations among sub-bands below and above the Fermi level at room temperature. We synergize them in a new class of nanocomposites based on zeolitic imidazolate framework-8 (ZIF-8) and report selective sensing of CH in ∼10 parts-per-billion (ppb) with a determined limit of detection of ∼0.

On growth, buckling, and rupture of aneurysms: Cylindrical tube analogy.

Aneurysms are localized bulges of arteries; and they can rupture with fatal consequences. Complex mechanobiological factors preclude in vivo testing to assess the rupture risk of an aneurysm, and size based criteria are often used in clinical practice to guide surgical interventions. It is often found that tortuous and buckled aneurysms can exceed the size recommended for surgical intervention, and yet do not rupture.