With the continual miniaturization of electronic devices, there is an urgent need to understand the electron emission and the mechanism of electrical breakdown at nanoscale. For a nanogap, the complete process of the electrical breakdown includes the nano-protrusion growth, electron emission and thermal runaway of the nano-protrusion, and plasma formation. This review summarizes recent theories, experiments, and advanced atomistic simulation related to this breakdown process. First, the electron emission mechanisms in nanogaps and their transitions between different mechanisms are emphatically discussed, such as the effects of image potential (of different electrode’s configurations), anode screening, electron space-charge potential, and electron exchange-correlation potential. The corresponding experimental results on electron emission and electrical breakdown are discussed for fixed nanogaps on substrate and adjustable nanogaps, including space-charge effects, electrode deformation, and electrical breakdown characteristics. Advanced atomistic simulations about the nano-protrusion growth and the nanoelectrode or nano-protrusion thermal runaway under high electric field are discussed. Finally, we conclude and outline the key challenges for and perspectives on future theoretical, experimental, and atomistic simulation studies of nanoscale electrical breakdown processes.
Category: nanotechnology – Page 48
Light-driven molecular motors were first developed nearly 25 years ago at the University of Groningen, the Netherlands. This resulted in a shared Nobel Prize for Chemistry for Professor Ben Feringa in 2016. However, making these motors do actual work proved to be a challenge. A new paper from the Feringa lab, published in Nature Chemistry on 26 April, describes a combination of improvements that brings real-life applications closer.
First author Jinyu Sheng, now a postdoctoral researcher at the Institute of Science and Technology Austria (ISTA), adapted a “first generation” light-driven molecular motor during his Ph.D. studies in the Feringa laboratory. His main focus was to increase the efficiency of the motor molecule. “It is very fast, but only 2% of the photons that the molecule absorbs drive the rotary movement.”
This poor efficiency can get in the way of real-life applications. “Besides, increased efficiency would give us better control of the motion,” adds Sheng. The rotary motion of Feringa’s molecular motor takes place in four steps: two of them are photochemical, while two are temperature-driven. The latter are unidirectional, but the photochemical steps cause an isomerization of the molecule that is usually reversible.
A newly developed nanomaterial that mimics the behavior of proteins could be an effective tool for treating Alzheimer’s and other neurodegenerative diseases. The nanomaterial alters the interaction between two key proteins in brain cells—with a potentially powerful therapeutic effect.
The innovative findings, recently published in the journal Advanced Materials, were made possible thanks to a collaboration between University of Wisconsin–Madison scientists and nanomaterial engineers at Northwestern University.
The work centers around altering the interaction between two proteins that are believed to be involved in setting the stage for diseases like Alzheimer’s, Parkinson’s and amyotrophic lateral sclerosis, or ALS.
In the quest for more efficient and sustainable energy solutions, a multi-university research team has reached a significant milestone in capacitor technology. Researchers from the University of Houston, Jackson State University and Howard University have developed a new type of flexible high-energy-density capacitor, which is a device that stores energy.
Though the prototype device is just 1-inch by 1-inch, scaled-up versions of this innovation could potentially revolutionize energy storage systems across various industries, including medical, aviation, auto (EV), consumer electronics and defense.
The researchers shared the study details in a paper titled “Ultrahigh Capacitive Energy Density in Stratified 2D Nanofiller-Based Polymer Dielectric Films,” published in the journal ACS Nano.
DNA nanostructures can perform some of the complex robotic fabrication process for manufacturing and self-replication. Building things and performing work with nanorobots has been a major technical and scientific goal. This has been done and published in the peer reviewed journal Science. Nadrian C. “Ned” Seeman (December 16, 1945 – November 16, 2021) was an American nanotechnologist and crystallographer known for inventing the field of DNA nanotechnology. He contributed enough to this work published in 2023 to be listed as a co-author.
Seeman’s laboratory published the synthesis of the first three-dimensional nanoscale object, a cube made of DNA, in 1991. This work won the 1995 Feynman Prize in Nanotechnology. The concept of the dissimilar double DNA crossover introduced by Seeman, was important stepping stone towards the development of DNA origami. The goal of demonstrating designed three-dimensional DNA crystals was achieved by Seeman in 2009, nearly thirty years after his original elucidation of the idea.
The concepts of DNA nanotechnology later found further applications in DNA computing, DNA nanorobotics, and self-assembly of nanoelectronics. He shared the Kavli Prize in Nanoscience 2010 with Donald Eigler for their development of unprecedented methods to control matter on the nanoscale.
Unlike the rigid skeletons within our bodies, the skeletons within individual cells—cytoskeletons—are changeable, even fluid. And when these cytoskeletons reorganize themselves, they do more than support different cell shapes. They permit different functions.
Little wonder, then, that scientists who build artificial cells hope to create synthetic cytoskeletons that act like natural cytoskeletons. Synthetic cytoskeletons capable of supporting dynamic changes in cell shape and function could enable the development of novel drug delivery systems, diagnostic tools, and regenerative medicine applications.
Synthetic cytoskeletons have incorporated building blocks such as polymers, small molecules, carbon nanotubes, peptides, and DNA nanofilaments. Mostly DNA nanofilaments. Although they offer programmability, they can be hard to fine tune. To get around this difficulty, scientists based at UNC Chapel Hill led by Ronit Freeman, PhD, investigated the relatively unexplored possibilities offered by peptides. Specifically, the scientists engineered artificial cells using a programmable peptide–DNA nanotechnology approach.
Science And Technology For Emerging National Security Threats — Dr. Sean Kirkpatrick, Ph.D. — Nonlinear Solutions LLC — Fmr. Director, All-domain Anomaly Resolution Office (AARO), United States Department of Defense.
Dr. Sean Kirkpatrick, Ph.D. is Owner of Nonlinear Solutions LLC., an advisory group that provides strategic scientific and intelligence consulting services, with a focus on emerging science and technology trends, to clients in both the defense and intelligence communities.
Dr. Kirkpatrick recently retired from federal Senior Service in December 2023 and prior to his current responsibilities he answered to the Deputy Secretary of Defense to stand-up and lead the All-domain Anomaly Resolution Office (AARO — https://www.aaro.mil/) in early 2022, leading the U.S. government’s efforts to address Unidentified Anomalous Phenomena (UAP) using a rigorous scientific framework and a data-driven approach.
PRESS RELEASE — Toshiba Europe Ltd. and Single Quantum B.V. have collaborated to test and validate long-distance deployments of Quantum Key Distribution (QKD) technology. Following extended validation testing of Toshiba’s QKD technology and Single Quantum’s superconducting nanowire single photon detectors (SNSPDs), both companies are pleased to announce a solution that substantially extends the transmission range for QKD deployment over fibre connections, up to and beyond 300km.
QKD uses the quantum properties of light to generate quantum secure keys that are immune to decryption by both high performance conventional and quantum computers. Toshiba’s QKD is deployed over fibre networks, either coexisting with conventional data transmissions on deployed ‘lit’ fibres, or on dedicated quantum fibres.
Toshiba’s unique QKD technology can deliver quantum secure keys in a single fibre optic link at distances of up to 150km using standard integrated semiconductor devices. Achieving longer distance QKD fibre transmission is challenging due to the attenuation of the quantum signals along the fibre length, (the optical loss of the fibre link). To provide extended QKD transmission, operators typically concatenate fibre links together with trusted nodes along the fibre route which house QKD systems that relay the secret keys.
Human mini-lungs grown by University of Manchester scientists can mimic the response of animals when exposed to certain nanomaterials. The study is published in Nano Today.
T-Cell Priming Immunotherapies To Provide Broad And Robust, Long-Term Immunity — Prof. Dr. Thomas Rademacher, MD, PhD — CEO & Co-Founder, Emergex Vaccines
Professor Dr. Thomas Rademacher, MD, PhD, is CEO and Co-Founder of Emergex (https://emergexvaccines.com/), a company that has developed a novel nanoparticle-based vaccine technology to deliver synthetic viral fragments via microneedles on a skin-adhesive patch. Emergex’s approach works on the principle of priming immune T-cells, opening the door for the development of universal vaccines against highly mutagenic viruses such as the seasonal flu and covid. T-cell priming offers a superior inoculation strategy over traditional vaccines, which rely on the body’s generation of antibodies and fail to keep up with seasonal mutations.
A serial entrepreneur, Professor Rademacher also serves as Emeritus Professor of Molecular Medicine at University College London (UCL) and is widely considered one of the founders of biotech from the early 1980s (having been involved in many of it’s core disciplines – from recombinant proteins, to monoclonal antibodies, to glycobiology).