By Becky Oskin
Solar cells made from perovskites have sparked great excitement in recent years because the crystalline compounds boast low production costs and high energy efficiencies. Now UC Davis scientists have found that some promising compounds — the hybrid lead halide perovskites — are chemically unstable and may be unsuited for solar cells.
“We have proven these materials are highly unlikely to function on your rooftop for years,” said Alexandra Navrotsky, interdisciplinary professor of ceramic, earth, and environmental materials chemistry at UC Davis and director of the Nanomaterials in the Environment, Agriculture, and Technology (NEAT) organized research unit.
Our electronic devices are based on what happens when different materials are layered together: “The interface is the device,” as Nobel laureate Herbert Kroemer famously claimed over 40 years ago. Right now, our microchips and memory devices are based on the movement of electrons across and near interfaces, usually of silicon, but with limitations of conventional electronics become apparent, researchers are looking at new ways to store or process information. These “heterostructures” can also find applications in advanced batteries and fuel cells.
Now physicists at UC Davis have observed what’s going on at some of these interfaces as oxygen ions react with different metals, causing drastic changes in magnetic and electronic properties.
UC Davis researchers have developed a way to use the empty shell of a Hepatitis E virus to carry vaccines or drugs into the body. The technique has been tested in rodents as a way to target breast cancer, and is available for commercial licensing through UC Davis Office of Research.
Hepatitis E virus is feco-orally transmitted, so it can survive passing through the digestive system, said Marie Stark, a graduate student working with Professor Holland Cheng in the UC Davis Department of Molecular and Cell Biology.
A new virus-killing peptide springs from an unexpected source: another virus, Hepatitis C.
Now biomedical engineers at UC Davis and Nanyang Technological University, Singapore show how the HCV alpha-helical (AH) peptide can make holes in the types of membranes that surround viruses. The work is published Jan. 5 in Biophysical Journal.
HCV-AH is known to be active against a wide range of viruses including West Nile, dengue, measles and HIV.
The HCV-AH peptide appears to target an Achilles’ heel common to many viruses, most likely a property of the lipid coating or envelope, said study author Atul Parikh, professor of biomedical engineering at UC Davis. That means that it’s less likely that viruses can readily evolve to become resistant to the peptide.
By Holly Ober
Thermal ablation with magnetic resonance–guided focused ultrasound surgery (MRgFUS) is a noninvasive technique for treating fibroids and cancer. New research from UC Davis shows that combining the technique with chemotherapy can allow complete destruction of tumors in mice.
MRgFUS combines an ultrasound beam that heats and destroys tissue with a magnetic resonance imaging to guide the beam and monitor the effects of treatment. The effectiveness of the treatment can be limited by the need to spare normal tissue or critical structures on the tumor margins, as well as the need to eliminate micrometastases.
An exotic, swirling object with the sci-fi name of a “magnetic skyrmion” could be the future of nanoelectronics and memory storage. Physicists at UC Davis and the National Institute of Standards and Technology (NIST) have now succeeded in making magnetic skyrmions, formerly found at temperatures close to absolute zero, at room temperature.
“This is a potentially new way to store information, and the energy costs are expected to be extremely low,” said Kai Liu, professor of physics at UC Davis and corresponding author of a paper on the work, published in the journal Nature Communications Oct. 8.
By Jocelyn Anderson
Sponge-like nanoporous gold could be key to new devices to detect disease-causing agents in humans and plants, according to UC Davis researchers.
In two recent papers in Analytical Chemistry (here & here), a group from the UC Davis Department of Electrical and Computer Engineering demonstrated that they could detect nucleic acids using nanoporous gold, a novel sensor coating material, in mixtures of other biomolecules that would gum up most detectors. This method enables sensitive detection of DNA in complex biological samples, such as serum from whole blood.
UC Davis is a partner in new $610 million institute for photonics manufacturing innovation announced July 27 by Vice President Joe Biden at an event in Greece, N.Y.
The Integrated Photonics Institute for Manufacturing Innovation (IP-IMI) aims to stimulate new investment and industrial growth based on photonics technology, which uses light, rather than electrons, to carry information. Integrated photonics has the potential to pack more processing power onto a single chip, opening new possibilities in computing, telecommunications and related fields.
Integrated photonics device designed and fabricated in Professor Yoo’s lab at UC Davis. Credit: Binbin Guan
By Derrick Bang
Christopher Chapman, a Ph.D. student in the UC Davis Department of Biomedical Engineering, has been selected to attend the 65th annual Lindau Nobel Laureate Meeting, taking place June 28-July 3 in Lindau, Germany. Chapman will join a U.S. delegation of roughly 55 “young researchers,” as they’re designated by the Lindau committee.
The U.S. delegation will be among the Lindau Meeting’s approximately 650 global student and postdoctoral researchers from all three natural science Nobel Prize disciplines: medicine and physiology, physics, and chemistry. They’ll meet and confer with the 65 Nobel Laureates who will gather to interact with this next generation of leading scientists and researchers.
A hexane (six-carbon) molecule between two gold electrodes. A new UC Davis technique gives better measurements of these circuits. (Josh Hihath/UC Davis)
It’s nearly 50 years since Gordon Moore predicted that the density of transistors on an integrated circuit would double every two years. “Moore’s Law” has turned out to be a self-fulfilling prophecy that technologists pushed to meet, but to continue into the future, engineers will have to make radical changes to the structure or composition of circuits. One potential way to achieve this is to develop devices based on single-molecule connections.
Full post: Better measures of single molecule circuits
(452 words, 1 image, estimated 1:48 mins reading time)