A Membrane Deflection Experiment was used to test the mechanical response of freestanding thin film gold specimens. We present stress-strain curves obtained on films 0.3, 0.5 and 1.0 μm thick. Elastic modulus was consistently measured in the range of 53-55 GPa. Several size effects on the mechanical properties were observed including yield stress variations with membrane width and film thicknes...

We report a novel method to fabricate high quality 2-inch freestanding GaN substrate grown on cross-stacked carbon nanotubes (CSCNTs) coated sapphire by hydride vapor phase epitaxy (HVPE). As nanoscale masks, these CSCNTs can help weaken the interface connection and release the compressive stress by forming voids during fast coalescence and also block the propagation of threading dislocations (...

In this paper we investigate, both experimentally and theoretically, the competition between different failure mechanisms (stretching, bending and curvature l ocalization) in freestanding submicron thin films commonly used in micro-electromechanical systems. Micro structures made of elastic -brittle materials such as ultrananocrystalline diamond, diamond like carbon and silicon nitride, as well...

Structural defects in zinc oxide (ZnO) nanoparticles are complex and hard to be controlled during the synthesis, however, diversifying the chemical and physical performances. Here we report a rapid and low-temperature deposition method to fabricate planar-defect-rich ZnO nanoparticles on freestanding and aligned carbon nanotube films, different from common treatments which remove structural def...

We report a one-pot synthesis of silver nanoparticle-polymer composites (Ag-PNCs) in water by a novel finding involving the polycondensation of methoxybenzyl chlorides (MeO-BzCl) directly on Ag nanoparticle surfaces at room temperature, leading to highly soluble antimicrobial nanocomposites. The composites, which are soluble in a range of organic solvents, precipitate in the reaction vessel, ma...

Controlling the cellular microenvironment can be used to direct the cellular organization, thereby improving the function of synthetic tissues in biosensing, biorobotics, and regenerative medicine. In this study, we were inspired by the microstructure and biological properties of the extracellular matrix to develop freestanding ultrathin polymeric films (referred as "nanomembranes") that were f...

A review chapter 1 summarized the techniques and procedures for measuring the mechanical properties of freestanding films as of the end of 2000. Test methods can be characterized as direct or indirect. In the former, the property of interest is measured independently, e.g. Young’s modulus from separate measurements of force, area, and strain on a tensile specimen. In the latter, a model of the ...

Most of the basic research on the electrical behavior of CNTs has been carried out on individual or bundle nanotubes. More recently random or oriented CNT networks (CNTN) are emerging as new material for electronic application. We present the fabrication of thick and dense CNTNs, in the form of freestanding films, and the study of their electric resistance as a function of the temperature, from...

Conducting polymers show great promise as supercapacitor materials due to their high theoretical specific capacitance, low cost, toughness, and flexibility. Poor ion mobility, however, can render active material more than a few tens of nanometers from the surface inaccessible for charge storage, limiting performance. Here, we use semi-interpenetrating networks (sIPNs) of a pseudocapacitive poly...

Structural degradation and low conductivity of transition-metal oxides lead to severe capacity fading in lithium-ion batteries. Recent efforts to solve this issue have mainly focused on using nanocomposites or hybrids by integrating nanosized metal oxides with conducting additives. Here we design specific hierarchical structures and demonstrate their use in flexible, large-area anode assemblies...