Lifeboat Foundation

The classic film “Alien” was once promoted with the tagline “In space, no one can hear you scream.” Physicists Zhuoran Geng and Ilari Maasilta from the Nanoscience Center at the University of Jyväskylä, Finland, have demonstrated that, on the contrary, in certain situations, sound can be transmitted strongly across a vacuum region.

In a recent article published in Communications Physics they show that in some cases, a sound wave can jump or “tunnel” fully across a vacuum gap between two solids if the materials in question are piezoelectric. In such materials, vibrations (sound waves) produce an electrical response as well, and since an electric field can exist in vacuum, it can transmit the sound waves.

The requirement is that the size of the gap is smaller than the wavelength of the sound wave. This effect works not only in audio range of frequencies (Hz–kHz), but also in ultrasound (MHz) and hypersound (GHz) frequencies, as long as the vacuum gap is made smaller as the frequencies increase.

The ongoing AI revolution, set to reshape lifestyles and workplaces, has seen deep neural networks (DNNs) play a pivotal role, notably with the emergence of foundation models and generative AI. Yet, the conventional digital computing frameworks that host these models hinder their potential performance and energy efficiency. While AI-specific hardware has emerged, many designs separate memory and processing units, resulting in data shuffling and reduced efficiency.

IBM Research has pursued innovative ways to reimagine AI computation, leading to the concept of analog in-memory computing, or analog AI. This approach draws inspiration from neural networks in biological brains, where synapse strength governs neuron communication. Analog AI employs nanoscale resistive devices like Phase-change memory (PCM) to store synaptic weights as conductance values. PCM devices transition between amorphous and crystalline states, encoding a range of values and enabling local storage of weights with non-volatility.

A significant stride towards making analog AI a reality has been achieved by IBM Research in a recent Nature Electronics publication. They introduced a cutting-edge mixed-signal analog AI chip tailored for various DNN inference tasks. This chip, fabricated at IBM’s Albany NanoTech Complex, features 64 analog in-memory compute cores, each housing a 256-by-256 crossbar array of synaptic unit cells. Integrated compact, time-based analog-to-digital converters facilitate seamless transitions between analog and digital domains. Moreover, digital processing units within each core handle basic neuronal activation functions and scaling operations.

The tiny, floating blobs of mini-hearts were straight out of Frankenstein. Made from a mixture of human stem cells and a sprinkle of silicon nanowires, the cyborg heart organoids bizarrely pumped away as they grew inside Petri dishes.

When transplanted into rats with heart injuries they lost their spherical shape, spreading out into damaged regions and connecting with the hosts’ own heart cells. Within a month, the rats regained much of their heart function.

It’s not science fiction. A new study this month linked digital electrical components with biological cells into a cyborg organoid that, when transplanted into animal models of heart failure, melded with and repaired living, beating hearts.

The iconic movie Alien once claimed: “In space, no one can hear you scream.” However, physicists Zhuoran Geng and Ilari Maasilta from the Nanoscience Center at the University of Jyväskylä, Finland, beg to differ. Their recent research suggests that under specific conditions, sound can indeed be transmitted powerfully across a vacuum.

Their findings, published recently in the journal Communications Physics, reveal that in certain scenarios, sound waves can “tunnel” through a vacuum gap between two solid objects, provided those objects are piezoelectric. These particular materials generate an electrical response when subjected to sound waves or vibrations. Given that an electric field can be present in a vacuum, it can effectively carry these sound waves across.

The requirement is that the size of the gap is smaller than the wavelength of the sound wave. This effect works not only in the audio range of frequencies (Hz-kHz), but also in ultrasound (MHz) and hypersound (GHz) frequencies, as long as the vacuum gap is made smaller as the frequencies increase.

The Defense Advanced Research Projects Agency (DARPA) has announced a new program it says will develop synthetic metamaterials that could lead to breakthroughs in quantum computing and information science.

Called the Synthetic Quantum Nanostructures program, or SynQuaNon, the new DARPA initiative “aims to address this challenge with a fundamental science effort that seeks to develop synthetic metamaterials to enable enhanced functionalities and novel capabilities,” read a statement issued by the agency this week.

The program aims to produce a range of new quantum materials that will have a variety of uses in quantum computing and other information science applications.

They use a process called DNA origami.

This is according to a press release by the institution published on Friday.

TV screens equipped with quantum rods have the ability to generate 3D images for virtual reality devices. Now, MIT engineers have conceived of a way to precisely assemble arrays of quantum rods in the devices using scaffolds made of folded DNA that allow depth and dimensionality to be added to virtual scenes.

Continue reading “MIT scientists conceive of quantum rods for 3D screens” »

Flat screen TVs that incorporate quantum dots are now commercially available, but it has been more difficult to create arrays of their elongated cousins, quantum rods, for commercial devices. Quantum rods can control both the polarization and color of light, to generate 3D images for virtual reality devices.

Using scaffolds made of folded DNA, MIT engineers have come up with a new way to precisely assemble arrays of quantum rods. By depositing quantum rods onto a DNA scaffold in a highly controlled way, the researchers can regulate their orientation, which is a key factor in determining the polarization of light emitted by the array. This makes it easier to add depth and dimensionality to a virtual scene.

“One of the challenges with quantum rods is: How do you align them all at the nanoscale so they’re all pointing in the same direction?” says Mark Bathe, an MIT professor of biological engineering and the senior author of the new study. “When they’re all pointing in the same direction on a 2D surface, then they all have the same properties of how they interact with light and control its polarization.”

Researchers have developed an easy-to-build, low-cost 3D nanoprinting system that can create arbitrary 3D structures with extremely fine features. The new 3D nanoprinting technique is precise enough to print metamaterials as well as a variety of optical devices and components such as microlenses, micro-optical devices and metamaterials.

“Our system uses a two-step absorption process to realize 3D printing with accuracy reaching the nanometer level, which is suitable for commercial manufacturing,” said research team leader Cuifang Kuang from the Zhejiang Lab and Zhejiang University, both in China. “It can be used for a variety of applications such as printing micro or nanostructures for studying biological cells or fabricating the specialized optical waveguides used for virtual and augmented reality devices.”

Conventional high-resolution 3D nanoprinting approaches use pulsed femtosecond lasers that cost tens of thousands of dollars. In Optics Letters, Kuang and colleagues describe their new system based on an integrated fiber-coupled continuous-wave laser diode that is not only inexpensive but also easy to operate.

Multiple complementary DNA strands can be thermally annealed into desired entities to engineer DNA nanostructures. In a new study now published in Nature Nanotechnology, Caroline Rossi-Gendron and a team of researchers in chemistry, materials science and biology in France and Japan used a magnesium-free buffer containing sodium chloride, complex cocktails of DNA strands and proteins to self-assemble isothermally at room temperature or physiological temperature into user-defined nanostructures including nanogrids, DNA origami and single-stranded tile assemblies.

This self-assembly relied on thermodynamics, proceeding through multiple folding pathways to create highly configurable nanostructures. The method allowed the self-selection of the most stable shape in a large pool of competitive DNA strands. Interestingly, DNA origami can shift isothermally from an initially stable shape to a radically different one through an exchange of constitutive staple strands. This expanded the collection of shapes and functions obtained via isothermal self-assembly to create the foundation for adaptive nanomachines and facilitate evolutionary nanostructure discovery.

Self-assembly occurs when naturally occurring or rationally designed entities can embed necessary information to spontaneously interact and self-organize into functional superstructures of interest. Typically, synthetic self-assembled materials result from the organization of a repeating single component to create a stable supramolecular assembly containing micelles or colloidal crystals with a prescribed set of useful properties. Such constructs have limited reconfigurability, making it highly challenging to produce the desired structures.