Sept. 21, 2018
Livermore chemist Anna Marie Belle holds a sample case of chemical biosensors she fabricated for measuring neurotransmitters in the brain. Photo by Randy Wong/LLNL
Roughing it
Lawrence Livermore engineers and scientists have developed a new technique that enhances the performance of Lab-developed flexible thin-film biological sensors, increasing the sensitivity of the implantable arrays to chemicals for biosensing applications, among other performance improvements.
The researchers report on results achieved by electrochemically “roughening” the Lab-developed platinum multielectrode arrays, which resulted in increased surface area, enhanced capability to record and stimulate cell activity with the electrodes and improved adhesion of metal coatings. By placing the electrode arrays in an electrolyte solution and subjecting them to oxidation-reduction electrical pulses, researchers were able to enhance surface area by 44 times and improve detection of hydrogen peroxide by nearly three times due to greater electron transfer.
Researchers said the increased performance can enable detection of very small neurotransmitter concentrations in the brain or other chemicals of interest in the urine or other bodily fluids, allowing for quicker detection if chemical levels drift out of a healthy range. The research also marks the first time this level of performance enhancement was possible with roughening of thin film electrodes.
A peek at the southern hemisphere of Jupiter, as seen by the Juno spacecraft.
Late bloomer
Researchers at Switzerland’s University of Bern have discovered that Jupiter’s early growth was delayed approximately 2 million years.
This research tracks with results published by LLNL’s Thomas Kruijer, who explored meteorite composition to determine that the samples came from separate “reservoirs” in the solar system, an inner zone and an outer zone. This data suggested that Jupiter’s growth was delayed.
The Swiss team subjected the information to in-depth modeling to learn more about why this delay occurred. They believe that a similar phenomenon may have occurred in Uranus and Neptune, but more research is needed.
Lawrence Livermore recently received funding aimed at improving energy efficiency in buildings
A close shave
Researchers at Lawrence Livermore were awarded a grant of $3 million for a three-year project aimed at using building energy more efficiently to shave peak electric energy usage.
The grant was awarded by the Department of Energy’s Building Technologies Office (BTO) and the Office of Energy Efficiency & Renewable Energy (EERE).
LLNL’s project seeks to establish metrics of peak energy usage and energy shaving capabilities that can be used by grid operators to lower the cost of their services.
“With more data becoming available, we have more ideas about how buildings behave, and how the peak forms,” the project’s lead researcher Jhi-Young Joo said. “We want to process that data to be able to estimate how much of the peak can be shaved or shifted to help with grid operations. We’d like for grid operators to have accurate metrics in terms of how much buildings can provide in peak shaving capabilities when the grid needs reduction of energy consumption.”
This image captures a high-altitude cloud formation surrounded by swirling patterns in the atmosphere of Jupiter's North North Temperate Belt , which is one of Jupiter's many colorful, swirling cloud bands. Scientists have wondered for decades how deep these bands extend. Gravity measurements collected by Juno during its close flybys discovered that these bands of flowing atmosphere actually penetrate deep into the planet, to a depth of about 1,900 miles (3,000 kilometers). Credit: NASA
Jupiter comes through with flying colors
Scientists from Australia and Lawrence Livermore National Laboratory have helped to solve the mystery underlying Jupiter’s colored by looking at the interaction between atmospheres and magnetic fields.
Jupiter is a gaseous planet consisting mostly of hydrogen and helium. Several strong jet streams flow west to east in Jupiter’s atmosphere that are, in a way, similar to Earth’s jet streams. Clouds of ammonia at Jupiter’s outer atmosphere are carried along by these jet streams to form Jupiter’s colored bands, which are shades of white, red, orange, brown and yellow. Until recently, little was known about what happened below Jupiter’s clouds.
“The gas in the interior of Jupiter is magnetized, so we think our new theory explains why the jet streams go as deep as they do under the gas giant’s surface but don’t go any deeper,” said LLNL scientist Jeffrey Parker.
Lawrence Livermore researchers created inks made of gold and silver microparticles. After printing, the 3D parts were heated to allow the particles to coalesce into a gold-silver alloy. The parts were put into a chemical bath that removed the silver (a process called “dealloying”) to form porous gold within each beam or filament. Credit: Ryan Chen/LLNL
Gold is worth its weight
Nanoporous metals are superior catalysts for chemical reactions due to their large surface area and high electrical conductivity, making them perfect candidates for applications such as electrochemical reactors, sensors and actuators.
Lawrence Livermore researchers, along with their counterparts at Harvard University, report on the hierarchical 3-D printing of nanoporous gold, a proof of concept that researchers say could revolutionize the design of chemical reactors.
"By using 3-D printing we can realize macroporous structures with application-specific flow patterns,” said LLNL postdoctoral researcher Zhen Qi. “By creating hierarchical structures, we provide pathways for fast mass transport to take full advantage of the large surface area of nanoporous materials. It's also a way to save materials, especially precious metals."
Combining 3-D printing through extrusion-based direct ink writing and an alloying and dealloying process, researchers were able to engineer the nanoporous gold into three distinct scales, from the microscale down to the nanoscale.
