Scientists make it possible to 3D print your own sonic tractor beam

You can now, with some assembly, 3D print your very own tiny sonic tractor beam.

Thanks to the efforts of a research team at Bristol University, technology for a single-sided acoustic tractor beam has now been adapted to be printed and assembled by anyone with the inclination. The publically available specifications are based on the first single-sided acoustic tractor beam, developed last year.

The original technology was developed by Asier Marzo, then a doctoral student at the Public University of Navarre. The tractor beam, rather than using the long-possible sonic levitation to push objects around, functioned true to its name and was able to trap and pull objects using sound waves from only one direction.

Marzo, now a research assistant at the University of Bristol, led his team in changing the technology into something that anyone could produce. Their efforts, beyond adaptation, have resulted in the production of a fully detailed how-to video for the public and an open access paper in Applied Physics Letters that will lay out the results of their development work.

“Previously we developed a tractor beam, but it was very complicated and pricey because it required a phase array, which is a complex electronic system,” Marzo said. “In this paper, we made a simple, static tractor beam that only requires a static piece of matter.”

The principle change from the original technology to the new, more accessible version was the transition from an underlying complex structure that made use of expensive electronics to an architecture that produces the same results structurally rather than electronically. As the sound passes through these elements, the waves are shaped by the internal structure of the 3D printed material.

The sound wave is modulated using a metamaterial which consists of lots of tubes of varying lengths. After passing through said tubes, the sound has the correct phases to create the tractor beam. However, the team face difficulty in optimising this material design to allow common 3D printers to produce the same results as more precise instruments.

Beyond the simple appeal of owning your own tractor beam, the technology may have serious potential for studying low-gravity effects on biological samples. Microgravity research is already an emerging field of interest and the tractor beam may serve as an effective tool for furthering these studies.

“Recently there have been several papers about what happens if we levitate an embryo, how does it develop? Or what happens if we levitate bacteria?” Marzo said. “For instance, they discovered salmonella is three times more [virulent] when it’s levitated. Certain microorganisms react differently to microgravity.”

There are currently three designs of the tractor beam, each with a trapping profile suited to different object sizes as related to the wavelength of sound used. However, the team’s technology is still limited to objects around half the size of the wavelength. For practical frequencies, just above what humans can hear, this limits the current size of trappable objects to a few millimetres.

Researchers discover remains of “Triassic Jaws” who dominated the seas after Earth’s most severe mass extinction event

Researchers have discovered the fossil remains of an unknown large predatory fish called Birgeria: an approximately 1.8-meter-long primitive bony fish with long jaws and sharp teeth that swallowed its prey whole.

Swiss and US researchers led by the Paleontological Institute and Museum of the University of Zurich say the Birgeria dominated the sea that once covered present-day Nevada one million years after the mass extinction.

Its period of dominance began following “the most catastrophic mass extinction on Earth”, which took place about 252 million years ago – at the boundary between the Permian and Triassic geological periods.

Image courtesy of UZH. Featured image courtesy of Nadine Bösch

Up to 90% of the marine species of that time were annihilated, and before the discovery of the Birgeria, palaeontologists had assumed that the first predators at the top of the food chain did not appear until the Middle Triassic epoch about 247 to 235 million years ago.

“The surprising find from Elko County in northeastern Nevada is one of the most completely preserved vertebrate remains from this time period ever discovered in the United States,” emphasises Carlo Romano, lead author of the study.

Although, species of Birgeria existed worldwide. The most recent discovery belongs to a previously unknown species called Birgeria Americana, and is the earliest example of a large-sized Birgeria species, about one and a half times longer than geologically older relatives.

The researchers say the discovery of Birgeria is proof that food chains recovered quicker than previously thought from Earth’s most devastating mass extinction event.

According to earlier studies, marine food chains were shortened after the mass extinction event and recovered only slowly and stepwise.

However, finds such as the newly discovered Birgeria species and the fossils of other vertebrates now show that so-called apex predators (animals at the very top of the food chain) already lived early after the mass extinction.

“The vertebrates from Nevada show that previous interpretations of past biotic crises and associated global changes were too simplistic,” said Romano.

Revolutionary DNA sunscreen gives better protection the longer its worn

Researchers have developed a ground-breaking sunscreen made of DNA that offers significant improvements over conventional versions.

Unlike current sunscreens, which need to be reapplied regularly to remain effective, the DNA sunscreen improves over time, offering greater protection the longer it is exposed to the sun.

In addition, it also keeps the skin hydrated, meaning it could also be beneficial as a treatment for wounds in extreme or adverse environments.

Developed by researchers from Binghamton University, State University of New York, the innovative sunscreen could prove essential as temperatures climb and many are increasingly at risk of conditions caused by excessive UV exposure, such as skin cancer.

“Ultraviolet (UV) light can actually damage DNA, and that’s not good for the skin,” said Guy German, assistant professor of biomedical engineering at Binghamton University.

“We thought, let’s flip it. What happens instead if we actually used DNA as a sacrificial layer? So instead of damaging DNA within the skin, we damage a layer on top of the skin.”

The DNA sunscreen has the potential to become a standard, significantly improving the safety of spending time in the sun

The research, which is published today in the journal Scientific Reports, involved the development of thin crystalline DNA films.

These films are transparent in appearance, but able to absorb UV light; when the researchers exposed the film to UV light, they found that its absorption rate improved, meaning the more UV is was exposed to, the more it absorbed.

“If you translate that, it means to me that if you use this as a topical cream or sunscreen, the longer that you stay out on the beach, the better it gets at being a sunscreen,” said German.

The film will no doubt attract the attention of sunscreen manufacturers, who will likely be keen to commercialise such a promising product. However, the researchers have not said if there is any interest as yet, and if there is any clear timeline to it becoming a commercial product.

 

The film’s properties are not just limited to sun protection, however. The DNA film can also store water at a far greater rate than conventional skin, limiting water evaporation and increasing the skin’s hydration.

As a result, the film is also being explored as a wound covering, as it would allow the wound to be protected from the sun, keep it moist – an important factor for improved healing – and allow the wound to be monitored without needing to remove the dressing.

“Not only do we think this might have applications for sunscreen and moisturizers directly, but if it’s optically transparent and prevents tissue damage from the sun and it’s good at keeping the skin hydrated, we think this might be potentially exploitable as a wound covering for extreme environments,” said German.