Friday, August 07, 2026

 

A new way to build safer, more sustainable skyscrapers



Imperial College London and Arup pioneer a new approach to designing tall buildings that uses the building's own weight to reduce movement in high winds and earthquakes.




Imperial College London

GIF - Side by side demonstration of concept under seismic tests 

image: 

Response comparison between a conventionally rigid tower ('Rigid') and one with the proposed control mechanism ('Damped') under a seismic record.

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Credit: Miguel Martinez Paneda, Imperial College London





Key findings:

  • Up to 70% less movement in high winds than conventional tower design.
  • More than 50% lower structural loads, creating opportunities to reduce steel and concrete use.
  • One solution for wind and earthquakes, reducing earthquake displacements by 42% on average.

Extreme events continue to expose the vulnerability of our towns and cities. As urban populations grow and the climate changes, the need for buildings that protect people, recover quickly and use resources more efficiently has never been clearer.

Meeting these challenges has traditionally relied on designing tall buildings to remain as rigid as possible, resisting wind- and earthquake-induced motions through increased structural sizes and material usage. Researchers and engineers from Imperial College London and Arup have challenged that long-held assumption, developing a new approach that uses a building’s own mass to reduce movement in high winds and earthquakes. Instead of trying to eliminate movement, it accepts that buildings will move and puts that movement to work to improve the building’s performance. Tested through wind tunnel experiments and earthquake simulations, the approach reduced wind-induced accelerations and was shown to result in safer, more resilient and more sustainable tall buildings.

Recently highlighted by Nature, the research was led by Imperial’s Miguel Martínez Pañeda (Department of Civil and Environmental Engineering and Arup), with Professor Ahmed Y Elghazouli (Department of Civil and Environmental Engineering) working alongside Dr Kevin Gouder (Department of Aeronautics) and industry colleague Dr William Algaard (Arup).

Martínez Pañeda, PhD Researcher in the Department of Civil and Environmental Engineering and Principal Structural Engineering at Arup, said: "Movement is not automatically a flaw. Rather than adding extra weight or making the structure bigger to keep a building still, the approach turns a building’s own mass into a design asset, improving comfort, safety and material efficiency in both high winds and earthquakes."

Turning movement into a design asset

Tall buildings naturally sway in strong winds and earthquakes. A common solution to control its movement under wind is adding a tuned mass damper: a very large weight, often hundreds of tonnes, suspended near the top of a tower and designed to move against the building's motion. These systems are effective at improving occupant comfort in the wind, but they take up valuable floor space, require substantial reinforcement and do little to reduce the forces a building experiences during an earthquake. Designers often need separate systems to improve seismic performance.

The researchers instead asked a different question: what if part of the building itself became the damper? Their solution separates a group of usable floors near the top of the building from its central core, connecting them with springs and dampers. Those floors remain fully usable, but can move slightly and independently, using their own weight to absorb energy and control the building's motion in both strong winds and earthquakes.

Putting the idea to the test

To prove the concept, the team built a 1:300 scale model of a 300-metre tower and tested it in the National Wind Tunnel Facility’s 10ft x 5ft wind tunnel at Imperial’s Department of Aeronautics (one of few facilities in the world equipped for this kind of testing) alongside dynamic seismic tests in the Department of Civil and Environmental Engineering’s Structures Laboratory.

The results showed the system dramatically reduced how much the building moved. Peak accelerations fell by up to 71% and base moments by more than 50%, compared with a conventional rigid design. Under simulated earthquakes, top displacements dropped by 42% on average, while movement in the movable floors fell by up to 74%. The controlled movement between the floors and the core remained minimal, and it was proven that occupants would not notice the movement under normal conditions.

Dr Kevin Gouder, Advanced Research Fellow in the Department of Aeronautics, said: “These tests gave us the confidence that the concept isn’t just theoretically sound, it's mechanically robust and buildable with technology that already exists. Seeing the model in the tunnel respond exactly as the numerical models predicted was a real turning point for the project.”

One solution for two hazards

Because the system responds to both wind and earthquakes, it removes the need for separate damping systems altogether, an approach that becomes increasingly valuable as more tall buildings are constructed in regions exposed to both hazards.

Cities including Hong Kong, Manila, Miami and Taipei regularly experience typhoons or hurricanes, while many of the world's fastest-growing urban centres across Latin America and East and Southeast Asia are also located in areas of high seismic risk. The need for more resilient tall buildings has been highlighted by recent disasters. In March 2025, a magnitude 7.7 earthquake that struck Myanmar caused a 33-storey tower under construction in Bangkok to collapse.

Since the approach relies on established construction technologies, including springs, dampers and bearings already widely used in buildings, the researchers believe it could be adopted without adding significant cost or complexity. Reducing the forces a building must resist also means less concrete and steel are needed in its core, columns and foundations, cutting both cost and embodied carbon.

The team's next steps include larger-scale testing of a movable module and a pilot application on a real building design. The project marks the culmination of almost a decade of work. The idea first emerged from Martínez Pañeda's Imperial Master's thesis in 2016 before developing into an international research programme involving Imperial and Arup.

The project was funded by the Institution of Civil Engineers (ICE), with support from Arup and the Council on Tall Buildings and Urban Habitat. Access to the National Wind Tunnel Facility at Imperial was supported by the Engineering and Physical Sciences Research Council (EPSRC).


Video - Side by side demonstration of concept under seismic tests [VIDEO] 


View of the aeroelastic model in the Imperial 10x5 Wind Tunnel 

View of the aeroelastic model in the Imperial 10x5 Wind Tunnel

Credit

Imperial College London

Miniature accelerometers and a base load cell are paced under the model enabled accurate capture of the response. 

Miniature accelerometers and a base load cell are paced under the model enabled accurate capture of the response.

Miguel Martínez Pañeda performing small adjustments in the aeroelastic model between test runs 

Miguel Martínez Pañeda performing small adjustments in the aeroelastic model between test runs


Never-before-seen woven structure that forms naturally inside a crystal discovered



Discovery reveals a new type of organization in materials and expands our understanding of how complex structures emerge in nature




The Hebrew University of Jerusalem

Phase contrast microscope image of the woven fabric 

image: 

Phase contrast microscope image of the woven fabric

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Credit: J. Gelkop





Discovery reveals a new type of organization in materials and expands our understanding of how complex structures emerge in nature

For the first time, scientists have observed a three-dimensional woven structure forming naturally inside a crystal, revealing a previously unknown way in which matter can organize itself.

Published in Light: Science & Applications, the study reports the observation of a three-dimensional woven fabric of interlaced nano-dipole ensembles that emerges spontaneously in a ferroelectric crystal as it cools through its phase transition. Unlike conventional ferroelectric crystals, in which ferroelectric domains consist of aligned electric dipoles, the dipoles in this material spontaneously weave over and under one another, creating an intricate three-dimensional network that resembles woven fabric. a type of organization never before observed in a solid crystal.

The researchers also found that they could change small parts of the woven network using a tightly focused green laser. The light locally untangles the woven pattern without affecting the rest of the crystal. Heating the crystal and cooling it again restores the woven structure, but with a new pattern.

The international research team consisted of a synergy between three research groups that employed several advanced imaging techniques. The groups were led by Prof. Eugenio Del Re of Sapienza University of Rome, Prof. Feifei Xin of Nankai University, and Prof. Aharon J. Agranat of the Institute of Applied Physics at the Hebrew University of Jerusalem, together with colleagues from the University of Groningen.

The phenomenon was observed in specially grown KTN:Li (KLTN) crystals invented by Prof. Agranat, in which periodic variations in the chemical composition were introduced during the crystal growth, forming striation gratings. These crystals were invented originally by Prof. Agranat for implementing electroholographic photonic switching, but were found here to be a platform for a new state of matter.

The researchers believe the discovery could represent a broader physical principle. Because the woven network forms through spontaneous symmetry breaking, they suggest that similar topological structures may emerge in many other systems, from liquid crystals and superconductors to quantum materials.

The authors said: "This is the first time anyone has observed a woven structure emerging spontaneously inside a solid crystal. What makes it exciting is not only that it reveals a completely new form of organization in matter, but that it suggests we may have overlooked similar topological structures in many other physical systems. Sometimes nature is far more creative than our theories predict."

 

COSMOLOGY: an unusual death




Ludwig-Maximilians-Universität München




A Faint X-ray Flash Exposes a Dying Star's Missing Jet —a surprising discovery for the international team, which includes researchers from LMU.

A rare cosmic explosion has given astronomers an unprecedented look at a massive star in its final moments, revealing a missing link between ordinary stellar explosions, so-called supernovae, and gamma-ray bursts, the brightest and most powerful phenomena in the Universe.

The event, named EP260321a, was first detected by the Einstein Probe satellite as a brief flash of X-rays from a galaxy about 500 million light-years away. Scientists interpret the signal as a “shock breakout,” the moment when the shock wave from a star’s collapsing interior bursts through its surface and releases the first light of a supernova.

Shock breakouts are thought to occur in every massive star’s death, but they’re notoriously hard to catch. They last only a short time and shine brightest in X-rays. In the past two decades, astronomers have confidently identified just one other clear X-ray shock breakout, making EP260321a an exceptionally rare find.

The X-ray flash set off a worldwide observing campaign. Among the first to catch it was LMU’s 2.1-meter Fraunhofer Telescope at Wendelstein Observatory, which spotted a rapidly brightening supernova later named SN 2026gzf. Observations of how its light evolved showed it belonged to the class known as broad-lined Type Ic supernovae. This class of supernovae typically has material shooting out in a jet at nearly the speed of light, producing gamma-ray bursts.

“Stars die on a daily basis somewhere in the Universe. But it’s rare that something unusual happens close enough for our observations to reveal fundamentally new insights. EP260321a rang an alarm bell right away - an X-ray flash but no gamma-ray alert? A supernova in a nearby galaxy, embedded in a blue knot that had already been getting brighter for years? That’s not what is expected, and it set off a chase around the globe. Fortunately, we were well prepared for exactly this kind of opportunity with LMU’s observatories,” says LMU astrophysicist Daniel Gruen, who led the observations with Wendelstein and with the Hobby-Eberly Telescope in Texas.

Not a typical dying massive star

As it turned out, SN 2026gzf was not your typical dying massive star. Researchers were surprised to find no evidence of a gamma-ray burst or relativistic jet following the explosion. This is even more unexpected because the explosion itself was not weak at all. In fact, its characteristics match well with other supernovae that did produce gamma-ray bursts.

Brendan O’Connor, an astronomer and McWilliams Fellow at Carnegie Mellon University (CMU) and lead author of one of the papers presenting the analysis, published in The Astrophysical Journal Letters, combined the telescope data with observations from NASA’s Chandra X-ray Observatory (CXO) and the NRAO’s Karl G. Jansky Very Large Array (VLA) radio observatory to reveal the full nature of the event.

“SN 2026gzf looks remarkably similar to other energetic supernovae that have been linked to gamma-ray bursts before. Yet multi-wavelength follow-up observations using the most sensitive facilities found no evidence of a jet or an afterglow that is typically seen in those events,” says O’Connor. “One possibility is that a jet was initially present, but ‘choked,’ either by the surface of the star or by material surrounding it.”

Another piece of the puzzle came from the spectra, the fingerprint of light emitted by the supernova and the stars in the galaxy around it. Using LMU’s share of the Hobby-Eberly Telescope, the team obtained an integral field spectrum, an image in which every pixel splits its light into a rainbow, revealing detailed information about its source. “What we found in the spectrum is that the star that exploded had been born from a cloud of pristine gas - mostly hydrogen, with only about 15% of the metals our Sun and local environment contain,” explains Malte Busmann, a graduate student at LMU and co-author of the study, adding, “Well those metals are being added right now. Just four days after the shock breakout, we’re already catching the first glimpses of metals forged by the dying star being flung outward in all directions.”

The site of the explosion is indeed one of the least metal-enriched environments known for this type of supernova. Low-metallicity environments are often thought to help massive stars retain the rotation needed to launch fast jets, yet SN 2026gzf produced no typical gamma-ray-burst jet. The Hobby-Eberly Telescope observations therefore show that low metallicity alone cannot determine whether a dying star successfully produces a gamma-ray burst.

"When a massive star forms from such almost pristine gas, we expect it to eject roughly half of its original mass before it eventually explodes. So this fits with the interpretation of the jet being choked by material surrounding the star" says Joachim Puls, expert on massive stars and their outflows at LMU.

With an exceptionally faint X-ray shock breakout, combined with the absence of the fast-moving jets that typically power gamma-ray bursts, EP260321a/SN 2026gzf acts as a unique bridge between ordinary, non-relativistic supernova shock breakouts and the far more extreme, relativistic explosions that generate gamma-ray bursts.

This discovery establishes that energetic broad-lined Type Ic supernovae do not always produce a gamma-ray burst, a bright relativistic shock breakout, and suggests that massive stars can die through a wider range of pathways than previously recognized.

A glimpse into the future of time-domain astronomy

Together with spectra obtained with CMU’s share in the Southern African Large Telescope and the Dark Energy Spectroscopic Instrument, and images taken by the Dark Energy Camera and Rubin Observatory that LMU participates in, and the Zwicky Transient Facility, a high-fidelity picture of the event emerged. Additional late-time observations have been approved with the James Webb Space Telescope to further reveal the inner workings of the explosion, its geometry, and ejecta composition.

“This sequence of observations offers a glimpse into the future of time-domain astronomy. By coordinating large, repeated sky surveys with smaller, dedicated telescopes, we can learn so much more from the surprises the Universe has in store for us,” says Xander Hall, a graduate student at CMU and second author of the study.