A gallium cast used to make a channel system in a soft gel, mimicking blood vessels
Subramanian Sundaram/BU and Harvard University
Lab-grown organs for transplant are one step closer thanks to a technique for making artificial blood vessels using 3D printers and liquid metal.
One challenge in developing organs in the lab is to reproduce the microscopic structure of blood vessels that permeate the tissue. In the body, cells are supported by the extracellular matrix (ECM), a gel-like network of proteins such as collagen that acts as a natural scaffolding, giving structure to tissues and organs.
Building a home base on the moon will demand a steep supply of moon-based infrastructure: launch pads, shelter, and radiation blockers. But shipping Earth-based concrete to the lunar surface bears a hefty price tag. Sending just 1 kilogram (2.2 pounds) of material to the moon costs roughly $1.2 million, says Ali Kazemian, a robotic construction researcherat Louisiana State University (LSU). Instead, NASA hopes to create new materials from lunar soil and eventually adapt the same techniques for building on Mars.
Traditional concrete requires large amounts of water, a commodity that will be in short supply on the moon and critically important for life support or scientific research, according to the American Society of Civil Engineers. While prior NASA projects have tested compounds that could be used to make “lunarcrete,” they’re still working to craft the right waterless material.
So LSU researchers are refining the formula, developing a new cement based on sulfur, which they heat until it’s molten to bind material without the need for water. In recentwork, the team mixed their waterless cement with simulated lunar and Martian soil to create a 3D-printable concrete, which they used to assemble walls and beams. “We need automated construction, and NASA thinks 3D printing is one of the few viable technologies for building lunar infrastructure,” says Kazemian.
A curved wall is 3D printed from waterless concrete.
COURTESY OF ALI KAZEMIAN
Beyond circumventing the need for water, the cement can handle wider temperature extremes and cures faster than traditional methods. The group used a pre-made powder for their experiments, but on the moon and Mars, astronauts might extract sulfur from surface soil.
To test whether the concrete can stand up to the moon’s harsh environment, the team placed its structures in a vacuum chamber for weeks, analyzing the material’s stability at different temperatures. Originally, researchers worried that cold conditions on the dark side of the moon might cause the compound to turn into a gas through a process called sublimation, like when dry ice skips its liquid phase and evaporates directly. Ultimately, they found that the concrete can handle the lunar South Pole’s frigid forecast without losing its form.
A robot inspired by Cheerios releasing alcohol fuel with a fluorescent dye
Jackson K. Wilt et al. 2024
The same phenomena that let beetles float across ponds and cause Cheerios to clustertogether in your cereal bowl can be harnessed to make tiny floating robots.
One of these, the Marangoni effect, arises when a fluid with a lower surface tension rapidly spreads out across the surface of a fluid with higher surface tension. This effect is exploited by Stenus beetles, which have evolved to zip across ponds by secreting a substance called stenusin, as well as soap-powered toy boats.
To investigate how this could be used by engineers, Jackson Wilt at Harvard University and his colleagues 3D-printed round, plastic pucks around a centimetre in diameter. Inside each was an air chamber for buoyancy and a tiny fuel tank containing alcohol, which has a lower surface tension than water, in concentrations from 10 to 50 per cent. The alcohol gradually leaks out from the puck, propelling it across the surface of the water.
The team used alcohol as a fuel because it evaporates, unlike soap which eventually contaminates the water and spoils the Marangoni effect. It turned out that the stronger the alcohol, the better the result. “Beer would be quite bad,” says Wilt. “Vodka is probably the best thing you could use. Absinthe… you’d have a lot of propulsion.” At peak speeds, the robots moved at 6 centimetres per second, and some experiments saw the pucks propelled for as long as 500 seconds.
By printing pucks with more than one fuel outlet and by sticking them together the researchers could also create larger devices that traced out wide curves or spun on the spot. Using multiple pucks also let the researchers investigate the “Cheerios effect”, which is when the cereal or other similar floating objects cluster. This occurs because they form a meniscus, or curved surface, in fluid, and these surfaces are attracted towards each other.
Wilt says that the 3D-printed devices could be useful in education to help students intuitively grasp concepts related to surface tension, but could also see applications in environmental or industrial processes if carefully designed to create more complex and elegant behaviour.
For instance, if there was a substance that needs to be dispersed throughout an environment that could also serve as a suitable fuel, the robots could spread it around automatically. “Let’s say you have a body of water where you need to release some chemical, and you want to distribute it more evenly, or you have some chemical process in which you need to deposit the material over time,” says Wilt. “I feel like there’s some really interesting behaviour here.”
A rapid form of 3D printing that uses sound and light could one day produce copies of human organs made from a person’s own cells, allowing for a range of drug tests.
Traditional 3D printers build from a hard base, layer by layer. This is time consuming and risks damage to printed objects when they are removed from the printing bed. David Collins at the University of Melbourne and his colleagues have taken a different approach, which they call “dynamic interface printing”.
Scientists have discovered a technique whereby light can be bent around corners, inspired by the way clouds scatter sunlight. This type of light-bending could lead to advances in medical imaging, electronics cooling and even nuclear reactor design.
Daniele Faccio at the University of Glasgow, UK, and his colleagues say they are shocked this type of light scattering wasn’t noticed before. It works on the same basis as clouds, snow and other white materials that absorb light: once photons hit the surface of such a material, they are scattered in all directions, barely penetrating at all and getting reflected out the way they came. For instance, when sunlight hits a tall cumulonimbus cloud, it bounces off the top, making this part of the cloud appear bright white. But so little light reaches the bottom of the cloud that this part appears grey – despite being made up of the same water droplets.
“The light bounces around and sort of tries to get in, and it’s bouncing off all the molecules and the defects,” says Faccio. “And eventually what happens is it just gets reflected back because it can’t get in. This is this scattering.”
To replicate this process, the team 3D printed objects from opaque white material while leaving thin tunnels of clear resin within. When light is shone at the material, it travels into these tunnels and is scattered – just as light is on snow or clouds. However, instead of scattering randomly in every direction until they are evenly dispersed, the photons are directed to return to the resin tunnel by the opaque material. The team put this to use, creating a range of objects that steer light in an organised way.
3D-printed white blocks with curved channels guide scattering light
University of Glasgow
These 3D-printed objects are functionally similar to fibre optic cables, which route light along their length, but they operate on fundamentally different principles. Fibre optic cables steer light by infinitely reflecting internally. When photons attempt to leave a cable’s inner core of plastic or glass, they hit another material with a lower refractive index and are reflected back inside. In this way, light can be carried for kilometres at a time, even around bends.
The researchers say their material boosts light transmission by more than two orders of magnitude compared with solid blocks without the same clear tunnels, and also allows it to be directed around curves. This is much less efficient than fibre optic, and will therefore struggle to achieve the great distances that it does, but it is also very simple and cheap.
This method of light-bending could make use of existing tunnels of translucent material, such as tendons and fluid in the spinal column, to provide new ways to carry out medical imaging. Faccio says the exact same principle also works to direct heat and neutrons, and could therefore also find use in a range of engineering applications such as cooling systems and nuclear reactors.
“It wasn’t obvious that this would work at all. We were shocked,” says Faccio, who believes the phenomenon could easily have been discovered decades or even centuries ago. “It’s not like we’ve created or found some really niche, weird equation with some weird properties.”
There’s more to the future of Lotus than big electric SUVs. That’s what the British company once famous for its lightweight sports cars wants you to believe—and it’s why Lotus has revealed a striking new supercar concept, called Theory 1.
To be clear, this is not an electric rebirth of the Lotus Esprit, the wedge-shaped ’70s icon driven into the sea by James Bond. At least not yet. Lotus aficionados will notice its name isn’t “Type” followed by three numbers, as is concept car tradition, nor does it begin with an E, as almost all production Lotuses do. Instead, it’s a way of showcasing technology that Lotus has planned for future cars and, just maybe, a hint of a supercar to come.
Speaking exclusively to WIRED, Lotus design vice president Ben Payne said: “We wanted to recapture that sense of purity, but not to do a kind of pastiche of an Esprit, because that doesn’t make any sense. So it’s more about the spirit of that car, the logic of the design and how controlled it is in the execution.”
Thanks to weigh savings, Theory 1 has a range of 250 miles from a modest 70-kWh battery.
Photograph: Leon Chew
That sense of control is key to all aspects of the Theory 1. Lotus could have given it 2,000 horsepower to match its Evija flagship, but it settled at a more reasonable 987 hp (1,000 PS). It could have let its designers run wild with enormous aero structures, ground-effect fans, and other hypercar paraphernalia, or overdosed on concept car tropes like huge touchscreen displays, artificial intelligence, or a drone that takes off from the rear deck.
Instead, Lotus did what it is best known for and, in the apocryphal words of founder Colin Chapman, it “simplified, then added lightness.”
Payne explained: “There’s been this period of maximalism, and people having to do one-upmanship and go above, above, above. And I think we’ve reached that point where it plateaus in stylistic terms, and also in the demonstration of tech.” He adds, “We’re not in a crazy numbers race with this car.”
Seriously Quick, Remarkably Light
Although not crazy by 2024 EV standards, Lotus is still pitching the Theory 1 as a seriously quick supercar. It’s aiming for a range of 250 miles from a modest 70-kWh battery, an all-wheel-drive system with its rear motor bolted directly to the suspension, motorsport-style, a 0 to 62-mph time of under 2.5 seconds, and a top speed of 200 mph. That’s all the usual supercar boxes ticked, but it’s nothing to give Rimac sleepless nights—or indeed get awkwardly close to Lotus’ own $2.3 million Evija.
More important than outright power is weight. Lotus says the all-carbon Theory 1 has a target of sub-1,600 kg (3,500 lbs), or around 300 kg less than the Evija. To further drive the weight-saving point home, the car has just 10 “A-surface materials”—those being the materials you can see and touch without digging beneath the surface—compared to the industry average of 100, according to Lotus. The 10 include cellulose-based glass fiber, chopped carbon fiber, and titanium, as well as recycled forms of glazing, polyester, rubber, and aluminum.
It’s also sensibly sized, as far as modern supercars go, with a width of 2,000 mm (78.7 inches), a length of 4,490 mm (176.8 inches), and a height of 1,140 mm (44.9 inches). Add this relative sensibility to the ingeniously practical doors, three seats, and excellent visibility, and it’s easy to imagine what a production version could look like.
I’m a huge fan of resin 3D printers. While the liquid resin can be a little harder to work with than typical filament printers, the results are often much more detailed and look better. However, there are some limitations to the Elegoo Mars 3 that I used in the past. Things like its small print bed, or making sure it’s properly ventilated because resin printing can be toxic, mean I don’t turn to it as often as I’d like. The new Elegoo Saturn 3 Ultra, on the other hand, fixes all of these problems and more.
What I love most about resin printing is that it enables me to be an even bigger nerd. I have friends who play a lot of D&D, and I like to make minifigs for them. When I make costumes for Dragon Con, I find it easiest to print a lot of the accessories or details that I don’t have the skills to craft myself out of other materials like foam. With the larger print size and a better filtering system, the Saturn 3 Ultra 12K made my dreams of making nerdy stuff a more convenient reality.
Printing Space Galore
The biggest advantage of the Elegoo Saturn 3 Ultra 12K compared to other comparable 3D printers is just how much space you have to print. My Mars 3 has a build volume of 153.36 mm x 77.76 mm x 175 mm. That’s just under 7 inches tall, with a roughly 6- by 3-inch print bed. That’s good enough for printing D&D miniatures, small trinkets, or board game pieces. But it can get really restrictive if you want to do much that’s larger than that.
Photograph: Eric Ravenscraft
The Saturn 3 Ultra, on the other hand, has a positively massive 218.88 mm × 122.88 mm × 260 mm build volume. That means the print bed itself is around 8.6 inches by 4.8 inches, with a whopping 10.2 inches of height. Put more simply, the size of objects you can build is more than triple that of the Mars 3.
You might not think a couple of extra inches would matter, but it makes all the difference in the world. The printer came in handy when my partner wanted a prop for her Suzume costume. In this movie, the main character teams up with an animate children’s chair (just go with it) with a very distinct look.
We considered a number of ways to recreate this character. We could build it out of wood (we had no woodworking tools), we could make it out of foam (probably the smartest option, but we wanted it to be durable enough to survive a convention), or I could 3D-print some pieces and glue them all together. But the Mars 3 only had enough space to make a teeeeeny tiny version. And that’s not what my partner wanted.
The Saturn 3 Ultra came to the rescue. With a little finagling, I was able to fit every single piece of the chair–the back, the base, three long legs and two small supporting rods–into a single print. The whole print took about 14 long hours–the base of the chair was stretching the limits of that super tall print volume–but in the end, I was able to make all the parts needed for my partner’s costume companion with maybe a half hour of fiddling in 3D software, and a day of waiting for a print to finish.
Photograph: Eric Ravenscraft
Attention to Detail
Resin printers are so appealing because they can recreate detail that filament-based printers struggle with. They use ultraviolet light, projected through a digital display, to cure only the parts of a pool of liquid resin that are necessary for the print. And the screen in the base of the Saturn 3 Ultra 12 has a truly absurd level of detail.
The 12K in this printer’s full name refers to exactly the same thing it means in TVs. Your 4K TV has four thousand (roughly) lines of horizontal resolution. Likewise, the LCD screen in the Saturn 3 Ultra has a resolution of 11,520 x 5,120. When packed into a 10-inch display, it means the printer can create models with detail on a scale measured in tens of micrometers.
A man with a prosthetic right eye, which was not created via the AI approach
Stephen Bell, Ocupeye Ltd.
Prosthetic eyes that are designed by artificial intelligence and 3D printed require 80 per cent less time from human specialists compared with traditional manufacturing methods, potentially allowing many more people to benefit. A small trial also suggests that this approach leads to well-fitting prosthetics in most cases.
In the UK, for example, around 1 in 1000 people wear prosthetic eyes, which require highly trained ocularists to take moulds of the eye socket. Many people with such prosthetics also have an orbital implant to replace lost eye volume and create a surface to which muscles can be reattached, allowing natural eye movement. Prosthetics sit on top of this to provide a natural appearance.
The standard process of making a prosthetic takes around 8 hours, but now, Johann Reinhard at the Fraunhofer Institute for Computer Graphics Research in Darmstadt, Germany, and his colleagues have developed a method that automatically designs and 3D prints an implant to both fit the wearer’s eye socket and aesthetically match any remaining eye.
“It’s more comfortable to have an optical scan than having someone pouring this alginate [mould-making material] impression into your eye socket, particularly for children – it seems to be tricky to get them to [sit through] this procedure,” says Reinhard.
In the new process, an optical coherence tomography scanner uses light to create a 3D model of a person’s missing eye, so the back of the prosthetic can be designed for a close fit. A colour image is also taken of any remaining eye to make an aesthetic match.
The data is funnelled to an AI model, which then creates a design that is 3D printed by a machine that can operate at a resolution of 18 billion droplets per cubic centimetre.
Once the prosthetic is printed, it can be polished and adjusted to be a perfect fit by a human ocularist, a job that takes just 20 per cent of the time of the existing process.
A 3D-printed eye prosthetic designed by AI
Johann Reinhard, Fraunhofer IGD
In a trial of 10 people at Moorfields Eye Hospital in London, there were only two people for whom these prosthetics didn’t fit properly. Neither had an orbital implant, which Reinhard says is problematic for the scanner and the AI designer.
The team hopes the process can be refined to drastically reduce the cost required to create convincing prosthetics and make them available to more people. But Reinhard says it is unlikely that future prosthetics will be made without human experts at all.
“We see this like a tool for ocularists,” he says. “So it’s not something that’s meant to replace ocularists, but it’s a new process that they can use and we think that it provides better output in terms of appearance.”
Complex artificial organs could be created by 3D printing a mould of veins, arteries and capillaries in ice, casting that in organic material and then allowing the ice to melt away, resulting in a delicate, hollow network. This leaves a space for the intricate artificial blood vessels that are required to develop lab-grown internal organs.
Researchers have been working on artificial organs for decades to help meet the high global demand for transplants of the likes of hearts, kidneys and livers. But creating the blood vessel networks needed to keep them alive is still a challenge.
Existing techniques can grow artificial skin or ears, but any flesh or organ material dies off if more than 200 micrometres from a blood vessel, says Philip LeDuc at Carnegie Mellon University in Pennsylvania.
“It’s like twice the width of a hair; after you get past that, if there’s no access to nutrients, the cells start to die,” he says. Internal organs therefore require new processes if they are to become cheap and fast to manufacture.
LeDuc and his colleagues had experimented with printing blood vessels with wax that can be melted, but this requires reasonably high temperatures and can leave residue. “All of a sudden, one day, my student goes ‘why don’t we just use water – the most biologically compatible material in the world?’,” says LeDuc. “And I’m like ‘oh, yeah’. It still makes me laugh. It’s just so straightforward.”
They developed a technique that uses 3D printers to create a mould of the interior of an organ’s blood vessels in ice. In tests, these were then embedded in a gelatine material that hardens when exposed to ultraviolet light, before the ice melted away.
The team used a platform cooled to -35°C and a printer nozzle that dispensed hundreds of drops of water a second, allowing structures as small as 50 micrometres across to be printed.
LeDuc says the process is conceptually simple but needs to be tuned perfectly – dispense drops too fast and they don’t freeze quickly enough and fail to create the desired shape, but print them too slowly and they just form lumps.
The system is also affected by weather and humidity, so the researchers are investigating using artificial intelligence to keep the printer tuned to varying conditions.
They also used a version of water in which all the hydrogen is replaced by deuterium, a stable isotope of the element. This so-called heavy water has a higher freezing point and helps to create a smooth structure by avoiding unwanted crystallisation. Tests have shown it will be safe when creating artificial organs as deuterium isn’t radioactive, unlike some isotopes, says LeDuc.
