Tag Archives: 3D

How To Arrange Nanoparticules With a Vinaigrette

Materials scientists at Duke University have theorized a new “oil-and-vinegar” approach to engineering self-assembling materials of unusual architectures made out of spherical nanoparticles. The resulting structures could prove useful to applications in optics, plasmonics, electronics and multi-stage chemical catalysis. Left to their own tendencies, a system of suspended spherical nanoparticles designed to clump together will try to maximize their points of contact by packing themselves as tightly as possible. This results in the formation of either random clusters or a three-dimensional, crystalline structure.

But materials scientists often want to build more open structures of lower dimensions, such as strings or sheets, to take advantage of certain phenomena that can occur in the spaces between different types of particles.  In the new study, Gaurav Arya, associate professor of mechanical engineering and materials science at Duke, proposes a method that takes advantage of the layers formed by liquids that, like a bottle of vinaigrette left on the shelf for too long, refuse to mix together.

When spherical nanoparticles are placed into such a system, they tend to form a single layer at the interface of the opposing liquids. But they don’t have to stay there. By attachingoil” or “vinegarmolecules to the particles’ surfaces, researchers can make them float more on one side of the dividing line than the other.

The particles want to maximize their number of contacts and form bulk-like structures, but at the same time, the interface of the different liquids is trying to force them into two layers,” said Arya. “So you have a competition of forces, and you can use that to form different kinds of unique and interesting structures.”

Arya’s idea is to precisely control the amount that each spherical nanoparticle is repelled by one liquid or the other. And according to his calculations, by altering this property along with others such as the nanoparticles’ composition and size, materials scientists can make all sorts of interesting shapes, from spindly molecule-like structures to zig-zag structures where only two nanoparticles touch at a time. One could even imagine several different layers working together to arrange a system of nanoparticles.

In the proof-of-concept paper, the nanoparticles could be made out of anything. Gold or semiconductors could be useful for plasmonic and electrical devices, while other metallic elements could catalyze various chemical reactions. The opposing substrates that form the interface, meanwhile, are modeled after various types of polymers that could also be used in such applications.

The novel approach appeared online on March 25 in the journal ACS Nano.

Source: https://pratt.duke.edu/

Nanorobots Probe Into Cells

U of T Engineering researchers have built a set of magnetic tweezers’ that can position a nano-scale bead inside a human cell in three dimensions with unprecedented precision. The nano-bot has already been used to study the properties of cancer cells, and could point the way toward enhanced diagnosis and treatment.

Professor Yu Sun (MIE, IBBME, ECE) and his team have been building robots that can manipulate individual cells for two decades. Their creations have the ability to manipulate and measure single cells — useful in procedures such as in vitro fertilization and personalized medicine. Their latest study, published today in Science Robotics, takes the technology one step further.

The magnetic bead introduced into the cell and controlled to be navigated onto the nuclear envelope.

So far, our robot has been exploring outside a building, touching the brick wall, and trying to figure out what’s going on inside,” says Sun. “We wanted to deploy a robot in the building and probe all the rooms and structures.” The team has created robotic systems that can manipulate sub-cellular structures inside electron microscopes, but that requires freeze-drying the cells and cutting them into tiny slices. To probe live cells, other teams have used techniques such as lasers or acoustics.

Optical tweezers — using lasers to probe cells — is a popular approach,” says Xian Wang (MIE), the PhD candidate who conducted the research. The technology was honoured with 2018 Nobel Prize in Physics, but Wang says the force that it can generate is not large enough for mechanical manipulation and measurement he wanted to do. “You can try to increase the power to generate higher force, but you run the risk of damaging the sub-cellular components you’re trying to measure,” says Wang.

The system Wang designed uses six magnetic coils placed in different planes around a microscope coverslip seeded with live cancer cells. A magnetic iron bead about 700 nanometres in diameter — about 100 times smaller than the thickness of a human hair — is placed on the coverslip, where the cancer cells easily take it up inside their membranes. Once the bead is inside, Wang controls its position using real-time feedback from confocal microscopy imaging. He uses a computer-controlled algorithm to vary the electrical current through each of the coils, shaping the magnetic field in three dimensions and coaxing the bead into any desired position within the cell.

We can control the position to within a couple of hundred nanometers down the Brownian motion limit,” says Wang. “We can exert forces an order of magnitude higher than would be possible with lasers.”

In collaboration with Dr. Helen McNeil and Yonit Tsatskis at Mount Sinai Hospital and Dr. Sevan Hopyan at The Hospital for Sick Children (SickKids), the team used their robotic system to study early-stage and later-stage bladder cancer cells. Previous studies on cell nuclei required their extraction of from cells. Wang and Sun measured cell nuclei in intact cells without the need to break apart the cell membrane or cytoskeleton. They were able to show that the nucleus is not equally stiff in all directions. “It’s a bit like a football in shape — mechanically, it’s stiffer along one axis than the other,” says Sun. “We wouldn’t have known that without this new technique.”

They were also able to measure exactly how much stiffer the nucleus got when prodded repeatedly, and determine which cell protein or proteins may play a role in controlling this response. This knowledge could point the way toward new methods of diagnosing cancer. “We know that in the later-stage cells, the stiffening response is not as strong,” says Wang. “In situations where early-stage cancer cells and later-stage cells don’t look very different morphologically, this provides another way of telling them apart.”

According to Sun, the research could go even further. “You could imagine bringing in whole swarms of these nano-bots, and using them to either starve a tumour by blocking the blood vessels into the tumor, or destroy it directly via mechanical ablation,” says Sun. “This would offer a way to treat cancers that are resistant to chemotherapy, radiotherapy and immunotherapy.”

Source: https://news.engineering.utoronto.ca/

The Vatican’s Swiss Guards Are Now Using 3D Printed Helmets

For hundreds of years, the Swiss Guard have worn a distinctive, brightly-colored dress uniform while protecting the Pope and Vatican City, with only a couple of minor changes over the years. This year, they’re making a big change: the traditional, metal helmet — called a morion — is being replaced with ones that are 3D printed.


The uniforms and equipment of the Swiss Guard are imbued with tradition. The modern uniform was introduced in 1914, inspired by Renaissance-era artwork featuring the soldiers. Over the years, the Vatican has retained the traditional elements of the uniform, employing blacksmiths to provide replacement parts for their armor. Last year, the Swiss Guard announced that it ould replace the iconic helmet with one made out of PA-12, which were lighter and cheaper than their metal predecessors. This isn’t a trivial thing — as the soldiers spend a lot of time outdoors in the sun, the helmets would become uncomfortably hot, to the point where they would get burned.
The first batch of 98 of the new helmets (120 were ordered in all) were delivered to the Vatican on January 22nd, on the 513th anniversary of the founding of the Guard. Those new helmets were designed using scans of helmets from the 16th century, and are printed in just 14 hours using an HP 3D printer, as opposed to the older metal ones, which took nearly 130 hours to manufacture. The new morions also considerably lighter (weighting in at 570 grams; the ones they are replacing weighed 2 kilograms), are UV resistant, and incorporate ventilation slots to keep the soldiers’ heads cooler. There’s also no tradeoff on security for the soldiers, according to Swiss Guard spokesman Sergeant Urs Breitenmoser, because they’re used for ceremonial purposes such as papal masses and state visits.

Source: https://www.theverge.com/

How To Use The Body’s Inbuilt Healing System

Imperial researchers have developed a new bioinspired material that interacts with surrounding tissues to promote healing. Materials are widely used to help heal wounds: Collagen sponges help treat burns and pressure sores, and scaffold-like implants are used to repair broken bones. However, the process of tissue repair changes over time, so scientists are looking to biomaterials that interact with tissues as healing takes place.

Now, Dr Ben Almquist and his team at Imperial College London have created a new molecule that could change the way traditional materials work with the body. Known as traction force-activated payloads (TrAPs), their method lets materials talk to the body’s natural repair systems to drive healing.

CLICK ON THE IMAGE TO ENJOY THE VIDEO

The researchers say incorporating TrAPs into existing medical materials could revolutionise the way injuries are treated.

Our technology could help launch a new generation of materials that actively work with tissues to drive healing,” said Dr Almquist, from mperial’s Department of Bioengineering.
After an injury, cells ‘crawl’ through the collagen ‘scaffolds’ found in wounds, like spiders navigating webs. As they move, they pull on the scaffold, which activates hidden healing proteins that begin to repair injured tissue. The researchers in the study designed TrAPs as a way to recreate this natural healing method. They folded the DNA segments into three-dimensional shapes known as aptamers that cling tightly to proteins. Then, they attached a customisable ‘handle’ that cells can grab onto on one end, before attaching the opposite end to a scaffold such as collagen.
During laboratory testing of their technique, they found that cells pulled on the TrAPs as they crawled through the collagen scaffolds. The researchers tailor TrAPs to release specific therapeutic proteins based on which cells are present at a given point in time.

This is the first time scientists have activated healing proteins using differing cell types in man-made materials. The technique mimics healing methods found in nature. “Creatures from sea sponges to humans use cell movement to activate healing. Our approach mimics this by using the different cell varieties in wounds to drive healing,” explains Dr Almquist.”

This approach is adaptable to different cell types, so could be used in a variety of injuries such as fractured bones, scar tissue after heart attacks, and damaged nerves. New techniques are also desperately needed for patients whose wounds won’t heal despite current interventions, like diabetic foot ulcers, which are the leading cause of non-traumatic lower leg amputationsTrAPs are relatively straightforward to create and are fully man-made, meaning they are easily recreated in different labs and can be scaled up to industrial quantities.

TrAPs could harness the body’s natural healing powers to repair bone

TrAPs provide a flexible method of actively communicating with wounds, as well as key instructions when and where they are needed. This intelligent healing is useful during every phase of the healing process, has the potential to increase the body’s chance to recover, and has far-reaching uses on many different types of wounds. This technology could serve as a conductor of wound repair, orchestrating different cells over time to work together to heal damaged tissues,” said Dr Almquist.

The findings are published in Advanced Materials.

Source: https://www.imperial.ac.uk/

 

Chinese ‘Death Star’ For Submarines

China is developing a satellite with a powerful laser for anti-submarine warfare that researchers hope will be able to pinpoint a target as far as 500 metres below the surface. It is the latest addition to the country’s expanding deep-sea surveillance programme, and aside from targeting submarines – most operate at a depth of less than 500 metres – it could also be used to collect data on the world’s oceansProject Guanlan, meaning “watching the big waves”, was officially launched in May at the Pilot National Laboratory for Marine Science and Technology in Qingdao, Shandong. It aims to strengthen China’s surveillance activities in the world’s oceans, according to the laboratory’s website.

Scientists are working on the satellite’s design at the laboratory, but its key components are being developed by more than 20 research institutes and universities across the country. Song Xiaoquan, a researcher involved in the project, said if the team can develop the satellite as planned, it will make the upper layer of the seamore or less transparent”. “It will change almost everything,” Song said.

While light dims 1,000 times faster in water than in the air, and the sun can penetrate no more than 200 metres below the ocean surface, a powerful artificial laser beam can be 1 billion times brighter than the sun. But this project is ambitious – naval researchers have tried for more than half a century to develop a laser spotlight for hunting submarines using technology known as light detection and ranging (lidar). In theory, it works like this – when a laser beam hits a submarine, some pulses bounce back. They are then picked up by sensors and analysed by computer to determine the target’s location, speed and three-dimensional shape.

But in real life, lidar technology can be affected by the device’s power limitations, as well as cloud, fog, murky water – and even marine life such as fish and whales. Added to that, the laser beam deflects and scatters as it travels from one body of water to another, making it more of a challenge to get a precise calculation. Experiments carried out by the United States and former Soviet Union achieved maximum detection depths of less than 100 metres, according to openly available information. That range has been extended in recent years by the US in research funded by Nasa and the Defence Advanced Research Projects Agency (DARPA).

Source: https://www.scmp.com/

How To Neutralize Poisonous Carbon Monoxide

Scientists from the Nagoya Institute of Technology (NITech) in Japan have developed a sustainable method to neutralize carbon monoxide, the odorless poison produced by cars and home boilers.

Traditionally, carbon monoxide needs a noble metal – a rare and expensive ingredient – to convert into carbon dioxide and readily dissipate into the atmosphere. Although the noble metal ensures structural stability at a variety of temperatures, it’s a cost-prohibitive and finite resource and researchers have been anxious to find an alternative.

Now, a team led by Dr. Teruaki Fuchigami at the NITech has developed a raspberry-shaped nanoparticle capable of the same oxidation process that makes carbon monoxide gain an extra oxygen atom and lose its most potent toxicity.

Synthesis of cobalt oxide particles with complex, three-dimensional, raspberry-shaped nanostructures via hydrothermal treatment. Sodium sulfates functioned as bridging ligands to promote self-assembly and suppress particle growth. The highly ordered and complex surface nanostructure with 7-8 nm in diameter shows good structural stability and high activity in CO oxidation reaction.

We found that the raspberry-shaped particles achieve both high structural stability and high reactivity even in a single nanoscale surface structure,” said Dr. Fuchigami, an assistant professor in the Department of Life Science and Applied Chemistry at the NITech and first author on the paper.

The key, according to Dr. Fuchigami, is ensuring the particles are highly complex but organized. A single, simple particle can oxidize carbon monoxide, but it will naturally join with other simple particles. Those simple particles compact together and lose their oxidation abilities, especially as temperatures rise in an engine or boiler. Catalytic nanoparticles with single nano-scale and complex three-dimensional (3D) structures can achieve both high structural stability and high catalytic activity.

Th results were featured on the cover of the September issue of the journal, Nanomaterials.

Source: https://www.eurekalert.org/

VR Model Of The Milky Way Opens New Doors In Surgery

Using data from over a billion stars, a research team at Lund University in Sweden are developing an interactive 3D model of the Milky Way galaxy. This could enable new types of discoveries that aren’t possible with current tools – perhaps even unraveling how the Milky Way was formed. The data being used is from the Gaia satellite that was launched in 2013. It orbits the Earth and collects data from over a billion stars.

CLICK ON THE IMAGE TO ENJOY THE VIDEO

This will be the best map of the Milky Way we have so far. A Virtual Reality immersion is something we are very keen on exploring, as it can help us identify patterns and structures in very complex data”, explains Oscar Agertz, astronomy researcher at Lund University.

The research could also potentially allow surgeons to work together in medical examinations despite being on separate continents.

Source: https://www.lunduniversity.lu.se/