Researchers at Aalto University’s Department of Applied Physics found a new way to create tiny hurricanes of light — known to scientists as vortices — that can carry information. The method is based on manipulating metallic nanoparticles that interact with an electric field. The design method, belonging to a class of geometries known as quasicrystals, was thought up by Doctoral Researcher Kristian Arjas and experimentally realised by Doctoral Researcher Jani Taskinen, both from Professor Päivi Törmä’s Quantum Dynamics group. The discovery represents a fundamental step forward in physics and carries the potential for entirely new ways of transmitting information.

Half order and chaos

A vortex is in this case like a hurricane that occurs in a beam of light, where a calm and dark centre is surrounded by a ring of bright light. Just like the eye of a hurricane is calm due to the winds around it blowing in different directions, the eye of the vortex is dark due to the electric field of bright light pointing to different directions on different sides of the beam.

Previous physics research has connected what kind of vortices can appear with how much symmetry there is in the structure that produces them. For example, if particles in the nanoscale are arranged in squares the produced light has a single vortex; hexagons produce a double vortex and so on. More complex vortices require at least octagonal shapes.

Now Arjas, Taskinen and the team unlocked a method for creating geometric shapes that theoretically support any kind of vortex.

“This research is on the relationship between the symmetry and the rotationality of the vortex, i.e. what kinds of vortices can we generate with what kinds of symmetries. Our quasicrystal design is halfway between order and chaos,” Törmä says.

Good vibrations

In their study, the group manipulated 100,000 metallic nanoparticles, each roughly the size of a hundredth of a single strand of human hair, to create their unique design. The key lay in finding where the particles interacted with the desired electric field the least instead of the most.

‘An electrical field has hotspots of high vibration and spots where it is essentially dead. We introduced particles into the dead spots, which shut down everything else and allowed us to select the field with the most interesting properties for applications,’ Taskinen says.

The discovery opens a wealth of future research in the very active field of topological study of light. It also represents the early steps for a powerful way of transmitting information in domains where light is needed to send encoded information, including telecommunications.

‘We could, for example, send these vortices down optic fibre cables and unpack them at the destination. This would allow us to store our information into a much smaller space and transmit much more information at once. An optimistic guess for how much would be 8 to 16 times the information we can now deliver over optic fibre,’ Arjas says.

Practical applications and scalability of the team’s design are likely to take years of engineering. The Quantum Dynamics group at Aalto, however, have their hands full with research into superconductivity and improving organic LEDs.

The group used the OtaNano research infrastructure for nano-, micro- and quantum technologies in their pioneering study.

The research was published early November in Nature Communications.

Described in the open-access journal Zoosystematics and Evolution, Idiopyrgus eowynae and Idiopyrgus meriadoci were named in honour of Éowyn and Meriadoc Brandybuck from J.R.R. Tolkien’s iconic series.

In their research paper, the authors explain the name Idiopyrgus eowynae, stating, “Éowyn exemplifies courage, resilience, and resistance against darkness, both internal and external, standing against Gríma Wormtongue and the Witch-king of Angmar.”

Regarding Idiopyrgus meriadoci, they write, “Besides standing with Éowyn against the Witch-king in the Battle of the Pelennor Fields, Merry is also an example of the fight for nature conservation in Middle-earth, pushing the Ents into action and ultimately ending Saruman’s threat to Fangorn Forest.”

The discovered species are troglobitic and were found in a single limestone cave in the Serra do Ramalho karst area of Bahia state, northeastern Brazil. The gastropods belong to the family Tomichiidae, a group previously known for inhabiting surface freshwater environments but now shown to have adapted to subterranean ecosystems.

Both snails have unique periostracal hairs — thorn-like structures — on their shells, a feature uncommon among Brazilian freshwater snails. Their cave-specific adaptations include reduced pigmentation, fragile shells, and small size.

The Gruna do Pedro Cassiano cave, where the snails were discovered, is a fragile ecosystem threatened by water extraction, deforestation, and climate change. Due to the species’ limited habitat and environmental threats to their subterranean ecosystem, the authors recommend their classification as vulnerable. The findings highlight the importance of protecting Brazil’s subterranean biodiversity and raise concerns about the impact of human activities on these delicate ecosystems.

On his choice of Tolkien-inspired names for the new species, lead author Dr Rodrigo B. Salvador of the Finnish Museum of Natural History said, “I tend to use lots of pop culture references in my species names — from books, comics, Dungeons & Dragons, and video games. If we think about it, there is a long-standing tradition in taxonomy of using names from mythology and literature to name species.

“Granted, in the old days, those names mostly came from Greek and Roman myths and Shakespeare. Today, we have newer mythologies and literature classics, so in a way, we’re just continuing that tradition.”

The university announced on the 7th of November that the research team of Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering has succeeded in developing a microbial strain that efficiently produces pseudoaromatic polyester monomer to replace polyethylene terephthalate (PET) using systems metabolic engineering.

Pseudoaromatic dicarboxylic acids have better physical properties and higher biodegradability than aromatic polyester (PET) when synthesized as polymers, and are attracting attention as an eco-friendly monomer* that can be synthesized into polymers. The production of pseudoaromatic dicarboxylic acids through chemical methods has the problems of low yield and selectivity, complex reaction conditions, and the generation of hazardous waste.

To solve this problem, Professor Sang Yup Lee’s research team used metabolic engineering to develop a microbial strain that efficiently produces five types of pseudoaromatic dicarboxylic acids, including 2-pyrone-4,6-dicarboxylic acid and four types of pyridine dicarboxylic acids (2,3-, 2,4-, 2,5-, 2,6-pyridine dicarboxylic acids), in Corynebacterium, a bacterium mainly used for amino acid production.

The research team used metabolic engineering techniques to build a platform microbial strain that enhances the metabolic flow of protocatechuic acid, which is used as a precursor for several pseudoaromatic dicarboxylic acids, and prevents the loss of precursors.

Based on this, the genetic manipulation target was discovered through transcriptome analysis, producing 76.17 g/L of 2-pyrone-4,6-dicarboxylic acid, and by newly discovering and constructing three types of pyridine dicarboxylic acid production metabolic pathways, successfully producing 2.79 g/L of 2,3-pyridine dicarboxylic acid, 0.49 g/L of 2,4-pyridine dicarboxylic acid, and 1.42 g/L of 2,5-pyridine dicarboxylic acid.

In addition, the research team confirmed the production of 15.01 g/L through the construction and reinforcement of the 2,6-pyridine dicarboxylic acid biosynthesis pathway, successfully producing a total of five similar aromatic dicarboxylic acids with high efficiency.

In conclusion, the team succeeded in producing 2,4-, 2,5-, and 2,6-pyridine dicarboxylic acids at the world’s highest concentration. In particular, 2,4-, 2,5-pyridine dicarboxylic acid achieved production on the scale of g/L, which was previously produced in extremely small amounts (mg/L).

Based on this study, it is expected that it will be applied to various polyester production industrial processes, and it is also expected that it will be actively utilized in research on the production of similar aromatic polyesters.

Professor Sang Yup Lee, the corresponding author, said, “The significance lies in the fact that we have developed an eco-friendly technology that efficiently produces similar aromatic polyester monomers based on microorganisms,” and “This study will help the microorganism-based bio-monomer industry replace the petrochemical-based chemical industry in the future.”

The results of this study were published in the international academic journal, the Proceedings of the National Academy of Sciences of United States of America (PNAS) on October 30th.

This study was conducted with the support of the Development of Next-generation Biorefinery Platform Technologies for Leading Bio-based Chemicals Industry Project and the Development of Platform Technologies of Microbial Cell Factories for the Next-generation Biorefineries Project (Project leader: Professor Sang Yup Lee) from the National Research Foundation supported by the Ministry of Science and Technology and ICT of Korea.