This study demonstrated that an array of 96 microelectrodes can be implanted into the human peripheral nervous system for up to 1 month durations. Such an array could provide intuitive control of a virtual prosthetic hand with broad sensory feedback.

ABSTRACT:We have synthesized, characterized, and computationally validated the high Brunauer−Emmett− Teller surface area and hydrogen uptake of a new, noncatenating metal−organic framework (MOF) material, NU-111. Our results imply that replacing the phenyl spacers of organic linkers with triple-bond spacers is an effective strategy for boosting molecule-accessible gravimetric surface areas of MOFs and related high-porosity materials.T he chemical and structural diversity of metal−organic frameworks (MOFs) is one of the most notable characteristics of these materials. MOFs are hybrid materials composed of inorganic nodes and organic struts. 1−3 The most intriguing examples exhibit large internal surface areas; ultralow densities; uniform channels, cavities, and voids; and permanent porosity. Because of these exceptional properties, MOFs are being investigated for many potential applications, including gas storage, 4−8 gas and chemical separations, 9−12 chemical catalysis, 13,14 sensing, 15 ion exchange, 16 drug delivery, 17 and light harvesting. 18,19 Furthermore, the availability of singlecrystal structures of MOFs allows the use of computational modeling to calculate guest adsorption capabilities and other properties, which can help in screening MOFs for particular applications and improving our understanding of their performance. 20 The fact that these computational methods can be usefully applied gives MOFs a significant advantage over their amorphous counterparts.Rising concerns about climate change have intensified the search for environmentally friendly and renewable fuels such as water-derived H 2 , cellulosic ethanol, and photo-or electrochemically generated methane. Although molecular hydrogen is a compelling alternative to gasoline in many respects, highdensity storage is a significant challenge for the viability of hydrogen-powered vehicles. In order to drive 300 miles, 5 to 13 kg of H 2 are needed. Therefore, technologies that can efficiently concentrate gases at lower pressures, such as adsorption on porous materials, are desirable. The U.S. Department of Energy (DOE) has set targets for on-board H 2 storage systems for the year 2017: 5.5 wt % in gravimetric capacity and 40 g/L of volumetric capacity at an operating temperature in the range −40 to 60°C under a maximum delivery pressure of 100 atm. 21 Recently, automobile manufacturer Mercedes-Benz has announced its intention to use MOFs for mobile hydrogen storage at cryogenic temperatures. 22 Required are materials with surface areas of ∼24 million square feet of surface area per pound (4900 m 2 /g) and the ability to store substantial hydrogen at 435 psi (30 bar). MOFs are powerful contenders relative to other porous materials in meeting these conditions.We set out to make a MOF that satisfies both of the aforementioned requirements (∼4900 m 2 /g and high hydrogen uptake at 30 bar). We turned our attention to (3,24)-paddlewheel-connected MOF networks (rht topology), 23 for which catenation (interpenetration or interweaving of multiple frameworks)...

Surface modification and doping of graphitic-carbon catalyst support materials in fuel cell systems, particularly via nitrogen functionalization, has been shown to improve catalyst performance and durability through the optimization of catalystÀsupport interactions. To ascertain the nature of these interactions, Raman and X-ray photoelectron spectroscopy were used to study the structural and chemical modifications that nitrogen ion beam implantation caused to highly oriented pyrolitic graphite (HOPG) model catalyst support systems. Ion implantation doses explored in this work ranged over 2 orders of magnitude from 9.0 Â 10 14 to 9.6 Â 10 16 ions cm À2 . Low doses of nitrogen result in a large amount of structural damage with little incorporation of nitrogen. However, it was found that with increasing dosage the incremental increase in structural damage was marginal, while the percentage of nitrogen on the HOPG surface continued to increase significantly until both the level of damage and amount of nitrogen incorporated into the graphitic structure reached saturation. A near-surface nitrogen saturation level of approximately 6À8 atomic % was achieved with a dosage equal to or greater than 2.5 Â 10 16 ions cm À2 . The nitrogen implantation altered the initial pure sp 2 -hybridized graphitic carbon and resulted in the formation of sp 3 -hybridized carbon while also incorporating nitrogen into the graphitic network in the graphitic, pyridinic, and pyrrolic form. This work sets the stage for understanding the effect of the amount and functionality of nitrogen on the durability of model carbon-supported fuel cell electrocatalysts, discussed in Part II (10.1021/ jp112236n) of this work.

Recorded with appropriately scaled electrodes and grids, field potentials expose a more detailed representation of cortical network activity, enabling advanced analyses of cortical pathology and demanding applications such as brain-computer interfaces.

Single-walled carbon nanotube (SWCNT) fibers were engineered to become a scaffold for the storage of hydrogen. Carbon nanotube fibers were swollen in oleum (fuming sulfuric acid), and organic spacer groups were covalently linked between the nanotubes using diazonium functionalization chemistry to provide 3-dimensional (3-D) frameworks for the adsorption of hydrogen molecules. These 3-D nanoengineered fibers physisorb twice as much hydrogen per unit surface area as do typical macroporous carbon materials. These fiber-based systems can have high density, and combined with the outstanding thermal conductivity of carbon nanotubes, this points a way toward solving the volumetric and heat-transfer constraints that limit some other hydrogen-storage supports.