News from the NNI Community - Research Advances Funded by Agencies Participating in the NNI

Scientists at the University of California, Berkeley, and Stanford University have captured the real-time electrical activity of a beating heart, using a sheet of graphene to record an optical image of the faint electric fields generated by the rhythmic firing of the heart's muscle cells. The graphene camera represents a new type of sensor useful for studying cells and tissues that generate electrical voltages, including groups of neurons or cardiac muscle cells.

Scientists at the University of California, Berkeley, and Stanford University have captured the real-time electrical activity of a beating heart, using a sheet of graphene to record an optical image of the faint electric fields generated by the rhythmic firing of the heart's muscle cells. The graphene camera represents a new type of sensor useful for studying cells and tissues that generate electrical voltages, including groups of neurons or cardiac muscle cells.

The energy density of traditional lithium-ion batteries is approaching a saturation point that cannot meet the demands of the future – for example in electric vehicles. However, lithium metal batteries can provide double the energy per unit weight when compared to lithium-ion batteries. The biggest challenge hindering the application of lithium metal batteries is the formation of lithium dendrites, which are small, needle-like structures, over the lithium metal anode. These dendrites often continue to grow until they pierce the separator membrane, causing the battery to short-circuit and ultimately destroying it. Now, scientists at Boston University, Wayne State University, and Friedrich Schiller University in Germany have succeeded in preventing dendrite formation by using carbon nanomembrane-modified separators.

An international team of physicists led by the University of Minnesota has discovered that a unique superconducting metal is more resilient when used as a very thin layer only a few atomic layers thick. The research is the first step toward a larger goal of understanding unconventional superconducting states in materials, which could possibly be used in quantum computing in the future.

Researchers at the University of Pittsburgh have designed a new class of materials that are both sensors and nanogenerators. This type of material, called a self-aware metamaterial, acts as its own sensor, recording and relaying important information about the pressure and stresses on its structure. It also generates its own power and can be used for a wide array of sensing and monitoring applications. The most innovative facet of the work is its scalability: The same design works at both the nanoscale and the macroscale by tailoring the design geometry. 

Lithium-ion batteries work by moving lithium ions back and forth between two electrodes that temporarily store charge. Ideally, those ions are the only things moving in and out of the billions of nanoparticles that make up each electrode. But oxygen atoms leak out of the nanoparticles as lithium moves back and forth. So far, the details have been hard to pin down because the signals from these leaks are too small to measure directly. Now, researchers from Stanford University, the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, the U.S. Department of Energy's SLAC National Accelerator Laboratory, and Samsung Advanced Institute of Technology in South Korea have measured the leakage by looking at how oxygen loss modifies the chemistry and structure of the nanoparticles.

Engineers at Rice University have unveiled how a popular two-dimensional material, #MolybdenumDisulfide, flashes into existence during chemical vapor deposition. Knowing how the process works will give scientists and engineers a way to optimize the bulk manufacture of molybdenum disulfide and semiconducting crystals that are good bets to find a home in next-generation electronics. Chemical vapor deposition, often associated with graphene and carbon nanotubes, has been exploited to make a variety of two-dimensional materials by providing solid precursors and catalysts that sublimate into gas and react.

Widespread adoption of hydrogen-powered vehicles over traditional electric vehicles requires fuel cells that can convert hydrogen and oxygen safely into water – a serious implementation problem. Researchers at the University of Colorado Boulder and the University of California, Los Angeles, are addressing one aspect of that roadblock by developing new computational tools and models to better understand and manage the conversion process. The researchers developed models for metal nanostructures and oxygen, water, and metal interactions that are more than 10 times more accurate than current quantum methods.

A research team from the University of Massachusetts Amherst has created an electronic microsystem that can intelligently respond to information inputs without any external energy input, much like a self-autonomous living organism. The microsystem is constructed from a novel type of electronics that can process ultralow electronic signals and incorporates a device that can generate electricity from the ambient environment. Both of the key components of the microsystem are made from protein nanowires, a "green" electronic material that is renewably produced from microbes without generating electronic waste.

About 60% of drugs on the market have hydrophobic molecules as their active ingredients. These drugs, which are not soluble in water, can be difficult to formulate into tablets because they need to be broken down into nanocrystals to be absorbed by the human body. Now, a team of MIT chemical engineers has devised a simpler process for incorporating hydrophobic drugs into tablets or other drug formulations, such as capsules and thin films. Their technique, which involves creating a nanoemulsion of the drug and then crystallizing it, allows for a more powerful dose to be loaded per tablet.