Physical Sciences & Mathematics

Because of its extreme hardness, diamond is used as a cutting material in a multitude of fields, from aerospace engineering to geothermal energy. Using ultra-high pressures and temperatures, scientists have created a new form of diamond, which is now the hardest material known to humankind. Dr Guodong (David) Zhan and Timothy Eric Moellendick at Saudi Aramco, alongside Dr Duanwei He at Sichuan University, are the scientists behind this record-breaking substance, which will serve as an ‘indestructible’ cutting and drilling material.

The idea of unmanned drones flying together in expansive swarms may at first sound chaotic and unpredictable – yet with the right approach, these machines can enable their users to carry out coordinated and highly advanced missions. Through their research, John Sauter and colleagues at SoarTech have developed DSOARS – a transformative software that enables drones to mimic the behaviours of swarming animals found in nature. Their architecture now paves the way for real-world applications – from tracking forest fires and storms to aiding rescue missions.

Direct Laser Writing is a remarkably useful way to deposit intricately patterned materials onto surfaces. So far, however, the range of materials that can be used in the technique has been severely restricted. Now, Dr Hiroaki Nishiyama and his team at Yamagata University in Japan introduce an entirely new approach based on the unique properties of nanoparticles when suspended in a silver-based solution. When illuminated with ultra-short laser pulses, the setup can create highly stable patterns with sophisticated nanoscale structures – substantially broadening the range of materials available for use in the technique.

It is a widely-accepted scientific fact that the motions of molecules increase as their temperature rises. However, Dr Masahito Oh-eat the National Tsing Hua University in Taiwan has recently made a counterintuitive discovery in an organic semiconductor called ‘CADN’. Within a thin film of this material, his team has found that the motion of one part of the CADN molecule increases, while another part becomes more ordered as the temperature increases and approaches the material’s phase transition. This research is scientifically intriguing, but also has profound implications for improving display technologies based on organic semiconductor materials.

Organo-metallic perovskite crystals are widely known for their ability to boost the performance of solar cells, with efficiencies reaching 25% and beyond. This is because photons of light can mobilise electrons in these materials with very high efficiency. Professor László Forró and his team at Ecole Polytechnique Fédérale de Lausanne have realised that this same ability could be harnessed in the development of high-performance sensors that detect photons of various energies. By integrating perovskite with graphene or carbon nanotubes, the team’s detectors show outstanding sensitivity, with the ability to detect single photons. Their technologies are leading to new applications ranging from more sensitive medical diagnostics, to safer nuclear reactors.

The creation of giant atoms whose size is comparable to that of a grain of sand might sound like the stuff of science fiction, but in fact such species exist in nature and can now be created in the laboratory using advanced laser systems. Such exotic atoms, in which one electron is placed in a highly-energetic state, are termed Rydberg atoms, after the Swedish spectroscopist J. R. Rydberg who first characterised their properties. As might be expected, such extreme atoms possess very unusual physical and chemical properties. Their study has provided many new insights into the properties of Rydberg atoms themselves, their interactions with other atoms and molecules, and phenomena that arise from their collective interactions. The extreme properties of Rydberg atoms now enable emerging technological applications in sensing and quantum computation.

The pursuit to design more lightweight aircraft that can travel over greater distances never ceases. One area that has received much attention is the development of lighter and more aerodynamic antennas. Researchers at the NASA Glenn Research Center are at the forefront of this effort. The research team, which includes Jessica Cashman, Baochau Nguyen, Haiquan Guo, Marcos Pantoja, Kevin Cavicchi, and Mary Ann Meador, is designing flexible polymer materials that can be used to construct lightweight, low-drag antennas that lie along the surface of an aircraft.

A significant proportion of the world’s population has little to no access to clean water, and the water consumed by industrial activities continues to grow. Researchers from the Nanotechnology Enabled Water Treatment (NEWT) Center, which is headquartered at Rice University, are developing cutting-edge purification technologies that can provide communities with access to clean and safe drinking water. They are also creating new wastewater treatment methods that allow the reuse of industrial effluent, to minimise freshwater withdrawals by industries. Instead of conventional methods that use large amounts of chemicals and energy, NEWT technologies are chemical free, and often utilise solar energy.

Virtual and augmented reality technologies are now rapidly gaining traction in our society. Yet even as they improve, these devices continue to face major challenges relating to the wide variability of human vision. In their research, Dr Gordon Wetzstein and his colleagues at Stanford University explore innovative new ways to overcome these challenges, through the latest advances in both optics and vision science. In demonstrating ground-breaking innovations to near-eye displays and sensors, the team’s work could soon bring enormous benefits to users spanning a diverse spectrum of visual ability.

Climate change is mostly the result of elevated carbon dioxide emissions. Over the past two decades, research groups have been searching for new technologies that capture carbon dioxide from the atmosphere as an effective way of reversing climate change. Dr Radu Custelcean and his colleagues at the Oak Ridge National Laboratory in the US specialise in this endeavour. The team is developing novel materials and methods that filter carbon dioxide out of the air in an energy-efficient manner.