A team of physicists at CU Boulder has solved the mystery behind a perplexing phenomenon in the nano realm: why some ultra-small heat sources cool down faster if you pack them closer together. The findings, published today in the journal Proceedings of the National Academy of Sciences (PNAS), could one day help the tech industry design faster electronic devices that overheat less.
“Often, heat is a challenging consideration in designing electronics. You build a device then discover that it’s heating up faster than desired,” said study co-author Joshua Knobloch, postdoctoral research associate at JILA, a joint research institute between CU Boulder and the National Institute of Standards and Technology (NIST). “Our goal is to understand the fundamental physics involved so we can engineer future devices to efficiently manage the flow of heat.”
The research began with an unexplained observation: In 2,015 researchers led by physicists Margaret Murnane and Henry Kapteyn at JILA were experimenting with bars of metal that were many times thinner than the width of a human hair on a silicon base. When they heated those bars up with a laser, something strange occurred.
Cancer cell death is triggered within three days when X-rays are shone onto tumor tissue containing iodine-carrying nanoparticles. The iodine releases electrons that break the tumor’s DNA, leading to cell death. The findings, by scientists at Kyoto University’s Institute for Integrated Cell-Material Sciences (iCeMS) and colleagues in Japan and the US, were published in the journal Scientific Reports.
“Exposing a metal to light leads to the release of electrons, a phenomenon called the photoelectric effect. An explanation of this phenomenon by Albert Einstein in 1905 heralded the birth of quantum physics,” says iCeMS molecular biologist Fuyuhiko Tamanoi, who led the study. “Our research provides evidence that suggests it is possible to reproduce this effect inside cancer cells.”
A long-standing problem with cancer radiation therapy is that it is not effective at the center of tumors where oxygen levels are low due to the lack of blood vessels penetrating deeply into the tissue. X-ray irradiation needs oxygen to generate DNA-damaging reactive oxygen when the rays hit molecules inside the cell.
The material offers the high performance and stability needed for industrial-scale electrolysis, which could produce a clean energy fuel from seawater.
Hydrogen fuel derived from the sea could be an abundant and sustainable alternative to fossil fuels, but the potential power source has been limited by technical challenges, including how to practically harvest it.
Time-resolved photon counting plays an indispensable role in precision metrology in both classical and quantum regimes. Therein, time-correlated single-photon counting (TCSPC) [1] has been the key enabling technology for applications such as fluorescence lifetime microscopy [2], time-gated Raman spectroscopy [3], photon counting time-of-flight (ToF) 3D imaging [4], light-in-flight imaging [5], and computational diffuse optical tomography [6]. For all these applications, one of the most important figures of merit is the single-photon timing resolution (SPTR, also referred to as photon counting timing jitter). The TCSPC SPTR is limited by the available single-photon detectors. For example, photomultiplier tubes typically provide an SPTR larger than 100 ps [7]. Meanwhile, superconducting nanowire single-photon detectors have superior SPTR in the sub-10-ps range [8, 9]. However, cryogenic cooling significantly increases the system complexity. Single-photon avalanche diodes (SPADs) operate at moderate temperature, which makes them a popular choice for various applications mentioned above. Nevertheless, their SPTR is still limited to tens-of-picoseconds level [10]. On the other hand, orders-of-magnitude enhancement on SPTR is required for many challenging applications such as the study of ultrafast fluorescent decay dynamics [11,12].
In this Letter, we demonstrate a time-magnified TCSPC (TM-TCSPC) that achieves an ultrashort SPTR of 550 fs using an off-the-shelf single-photon detector. The key component is a quantum temporal magnifier using a low-noise high-efficiency fiber parametric time lens [13,14] based on four-wave mixing Bragg scattering (FWM-BS) [15 – 17]. A temporal magnification of 130 with a 97% photon conversion efficiency has been achieved while maintaining the quantum coherence of the signal under test (SUT). Detection sensitivity of -{95}\;rm{dBm}$ (0.03 photons per pulse), limited by the spontaneous Raman scattering noise, is possible and allows efficient processing and characterization of quantum-level SUT. The TM-TCSPC can resolve ultrashort pulses with a 130-fs pulse width difference at a 22-fs accuracy. When applied to photon counting ToF 3D imaging, the TM-TCSPC greatly suppresses the range walk error (RWE) that limits all photon counting ToF 3D imaging systems by 99.2% (130 times) and thus provides high depth measurement accuracy and precision of 26 µm and 3 µm, respectively. The TM-TCSPC is a promising solution for photon counting at the femtosecond regime that will benefit various research fields such as fluorescence lifetime microscopy, time-gated Raman spectroscopy, light-in-flight imaging, and computational diffuse optical tomography.
Check out our second promo for #transvision #future Summit 2021 (#madrid Oct. 8 — 12), featuring the optional dinner/cocktails we are scheduling, and 2 full-day #tours of several #unescoworldheritage sites and historical places near Madrid: Segovia, Ávila, Monsaterio de El Escorial & Valley of the Fallen on Oct. 11 and Alcalá de Henares, Aranjuez & Toledo on Oct. 12. It’s going to be espectacular! You don’t wanna miss those, so get your tickets now! 😊 Get your tickets here -> www.TransVisionMadrid.com.
The event itself will be a lot of fun, so make sure to register to come to Madrid in person, or to watch it via streaming (at a reduced price). There will be talks about #longevity #artificialintelligence #cryonics and much much more.
Promo by Sergio Tarrero for Alianza Futurista as Diamond Sponsor of TransVision Future Summit 2021. Alianza Futurista will also provide live video production, streaming and post production services for this event.
Humanity Plus Humanity Plus Magazine Ilustre Colegio Oficial de Médicos de Madrid (ICOMEM) Alcor Life Extension Foundation Cryonics Institute Cryonics Institute Posthuman Network Posthuman Network Cryonics4U Longevity Conferences Longevity for All International Longevity Alliance U.S. Transhumanist Party Transhumanist Party Australia Transhumanist Party Australia Group Transhumanist UK Rational Transhumanism Singularity University Ray Kurzweil Ray Kurzweil Singularity Ray Kurzweil Singularity Ray Kurzweil’s Singularity Singularity Hub Singularity Network Transhumanismo Brasil SingularityNET Singularitarianism Foresight Institute Lifeboat Foundation Machine Intelligence Research Institute KrioRus The Hedonistic Imperative — Paradise Engineering Future of Life Institute Future of Humanity Institute (Oxford University) The Long Now Foundation Global Catastrophic Risk Institute CLUB DE SEGUIDORES DE JOSÉ LUIS CORDEIRO (OFICIAL) Aubrey de Grey Dr. Aubrey de Grey HashtagTeam 🤩
http://www.TransVisionMadrid.com.
Promo by Sergio M.L. Tarrero for Alianza Futurista, proud Diamond Sponsor of #TransVision Future Summit 2021.
Spain will host the next global future summit #TransVision on October 8 9 and 10 2021. Humanity+ will be the main international organizer of this international event. Afterwards, during October 11 and 12 we will continue with informal conversations while traveling to UNESCO World Heritage Sites around Madrid: Alcalá de Henares, Aranjuez, Ávila, El Escorial, Segovia y Toledo. Every night will finish with optional cocktails in beautiful places for networking and meeting the participants and speakers.
The topics covered will be very broad, from recent medical advances, to artificial intelligence and robotics. The first keynote speakers will be the world famous Ray Kurzweil and Aubrey de Grey. Additionally, #TransVision 2021 will feature other keynote presentations, such as those from futurist movement pioneers Max More, Natasha Vita-More, Ben Goertzel and Anders Sandberg, members of Humanity+ and other leading institutions.
#TransVision 2021 collaborates with leading organizations working on futurist concepts such as life extension, artificial intelligence, robotics, nanotechnology, space travel, human enhancement, blockchain and other future technologies and trends. The first #TransVision conference was held in 1998 in the Netherlands, and since there we have hosted 14 international summits in cities like Berlin, Brussels, Caracas, Chicago, Helsinki, London, Madrid, Milano, Paris, Stockholm and Toronto.
#TransVision 2021 will be hosted in the historic Madrid College of Medicine (Ilustre Colegio Oficial de Médicos de Madrid), and there will be live streaming for those who can’t come in person to beautiful Madrid.
Some electronics can bend, twist and stretch in wearable displays, biomedical applications and soft robots. While these devices’ circuits have become increasingly pliable, the batteries and supercapacitors that power them are still rigid. Now, researchers in ACS’ Nano Letters report a flexible supercapacitor with electrodes made of wrinkled titanium carbide — a type of MXene nanomaterial — that maintained its ability to store and release electronic charges after repetitive stretching.
One major challenge stretchable electronics must overcome is the stiff and inflexible nature of their energy storage components, batteries and supercapacitors. Supercapacitors that use electrodes made from transitional metal carbides, carbonitrides or nitrides, called MXenes, have desirable electrical properties for portable flexible devices, such as rapid charging and discharging. And the way that 2D MXenes can form multi-layered nanosheets provides a large surface area for energy storage when they’re used in electrodes. However, previous researchers have had to incorporate polymers and other nanomaterials to keep these types of electrodes from breaking when bent, which decreases their electrical storage capacity. So, Desheng Kong and colleagues wanted to see if deforming a pristine titanium carbide MXene film into accordion-like ridges would maintain the electrode’s electrical properties while adding flexibility and stretchability to a supercapacitor.
The researchers disintegrated titanium aluminum carbide powder into flakes with hydrofluoric acid and captured the layers of pure titanium carbide nanosheets as a roughly textured film on a filter. Then they placed the film on a piece of pre-stretched acrylic elastomer that was 800% its relaxed size. When the researchers released the polymer, it shrank to its original state, and the adhered nanosheets crumpled into accordion-like wrinkles.
Nanoengineers at the University of California San Diego have developed COVID-19 vaccine candidates that can take the heat. Their key ingredients? Viruses from plants or bacteria.
The new fridge-free COVID-19 vaccines are still in the early stage of development. In mice, the vaccine candidates triggered high production of neutralizing antibodies against SARS-CoV-2, the virus that causes COVID-19. If they prove to be safe and effective in people, the vaccines could be a big game changer for global distribution efforts, including those in rural areas or resource-poor communities.
“What’s exciting about our vaccine technology is that is thermally stable, so it could easily reach places where setting up ultra-low temperature freezers, or having trucks drive around with these freezers, is not going to be possible,” said Nicole Steinmetz, a professor of nanoengineering and the director of the Center for Nano-ImmunoEngineering at the UC San Diego Jacobs School of Engineering.
A new study investigates tiny tumbling soft robots that can be controlled using rotating magnetic fields. The technology could be useful for delivering drugs to the nervous system. In this latest study, researchers put the robots through their paces and showed that they can climb slopes, tumble upstream against fluid flow and deliver substances at precise locations to neural tissue.
Would you let a tiny MANiAC travel around your nervous system to treat you with drugs? You may be inclined to say no, but in the future, “magnetically aligned nanorods in alginate capsules” (MANiACs) may be part of an advanced arsenal of drug delivery technologies at doctors’ disposal. A recent study in Frontiers in Robotics and AI is the first to investigate how such tiny robots might perform as drug delivery vehicles in neural tissue. The study finds that when controlled using a magnetic field, the tiny tumbling soft robots can move against fluid flow, climb slopes and move about neural tissues, such as the spinal cord, and deposit substances at precise locations.
Diseases in the central nervous system can be difficult to treat. “Delivering drugs orally or intravenously, for example, to target cancers or neurologic diseases, may affect regions of the body and nervous system that are unrelated to the disease,” explained Lamar Mair of Weinberg Medical Physics, a medical device company based in the US and an industrial partner on the study. “Targeted drug delivery may lead to improved efficacy and reduced side-effects due to lower off-target dosing.”
This novel material was made using a process that the team developed called a “float assembly method.” The float assembly takes advantage of the Marangoni effect, which occurs in two liquid phases with different surface tensions. When there is a gradient in surface tension, a Marangoni flow is generated away from the region with lower surface tension towards the region with higher surface tension. This means that dropping a liquid with lower surface tension on the water surface lowers the surface tension locally, and the resulting Marangoni flow causes the dropped liquid to spread thinly across the surface of the water.
The nanomembrane is created using a float assembly method which consists of a three-step process. The first step involves dropping a composite solution, which is a mixture of metal nanowires, rubber dissolved in toluene, and ethanol, on the surface of the water. The toluene-rubber phase remains above the water due to its hydrophobic property, while the nanowires end up on the interface between the water and toluene phases. The ethanol within the solution mixes with the water to lower the local surface tension, which generates Marangoni flow that propagates outward and prevents the aggregation of the nanowires. This assembles the nanomaterials into a monolayer at the interface between water and a very thin rubber/solvent film. In the second step, the surfactant is dropped to generate a second wave of Marangoni flow which tightly compacts the nanowires. Finally, in the third step, the toluene is evaporated and a nanomembrane with a unique structure in which a highly compacted monolayer of nanowires is partially embedded in an ultrathin rubber film is obtained.
Its unique structure allows efficient strain distribution in ultrathin rubber film, leading to excellent physical properties, such as a stretchability of over 1,000%, and a thickness of only 250 nm. The structure also allows cold welding and bi-layer stacking of the nanomembrane onto each other, which leads to a metal-like conductivity over 100,000 S/cm. Furthermore, the researchers demonstrated that the nanomembrane can be patterned using photolithography, which is a key technology that is widely used for manufacturing commercial semiconductor devices and advanced electronics. Therefore, it is expected that the nanomembrane can serve as a new platform material for skin electronics.
University of Houston researchers are reporting a breakthrough in the field of materials science and engineering with the development of an electrochemical actuator that uses specialized organic semiconductor nanotubes (OSNTs).
Currently in the early stages of development, the actuator will become a key part of research contributing to the future of robotic, bioelectronic and biomedical science.
“Electrochemical devices that transform electrical energy to mechanical energy have potential use in numerous applications, ranging from soft robotics and micropumps to autofocus microlenses and bioelectronics,” said Mohammad Reza Abidian, associate professor of biomedical engineering in the UH Cullen College of Engineering. He’s the corresponding author of the article “Organic Semiconductor Nanotubes for Electrochemical Devices,” published in the journal Advanced Functional Materials, which details the discovery.
