Particle accelerators are crucial tools in a wide variety of areas in industry, research and the medical sector. The space these machines require ranges from a few square meters to large research centers. Using lasers to accelerate electrons within a photonic nanostructure constitutes a microscopic alternative with the potential of generating significantly lower costs and making devices considerably less bulky.

Until now, no substantial energy gains were demonstrated. In other words, it has not been shown that electrons really have increased in speed significantly. A team of laser physicists at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) has now succeeded in demonstrating the first nanophotonic electron accelerator —at the same time as colleagues from Stanford University. The researchers from FAU have now published their findings in the journal Nature.

When people hear “particle accelerator,” most will probably think of the Large Hadron Collider in Geneva, the approximately 27 kilometer long ring-shaped tunnel which researchers from around the globe used to conduct research into unknown elementary particles. Such huge particle accelerators are the exception, however. We are more likely to encounter them in other places in our day to day lives, for example in medical imaging procedures or during radiation to treat tumors.

A team of researchers from TU Delft, University of Illinois, and MPI Göttingen has developed a nanoscale turbine made of DNA that can rotate in both directions depending on the salt concentration in the solution. This remarkable feat of nanotechnology could pave the way for new applications in drug delivery, biomimetics, and energy harvesting.

Natural turbines using DNA origami

A turbine is a device that converts the kinetic energy of a fluid into mechanical work. These are ubiquitous in our modern world, from wind farms to jet engines. They are also essential for life, as some biological molecules act as turbines to power cellular functions, such as the ATP synthase that produces energy for cells and the bacterial flagella that propel bacteria.

A collaborative team of researchers led by prof. Cees Dekker at TU Delft, in partnership with international colleagues, introduces a pioneering breakthrough in the world of nanomotors – the DNA origami nanoturbine. This nanoscale device could represent a paradigm shift, harnessing power from ion gradients or electrical potential across a solid-state nanopore to drive the turbine into mechanical rotations.

A new thermometer allows thermal mapping of surfaces with microscale resolution and enables studies of heat flow through materials at cryogenic temperatures.

To study tiny systems such as microelectronic components, researchers would like to map cryogenic temperatures of structures at the nanoscale. But current techniques involve some heating that can spoil the measurements. Now a research team has demonstrated a cryogenic thermometer that provides microscale resolution and that has little effect on the temperature of the system being measured [1]. Single molecules embedded in tiny crystals are the sensors, and they have millikelvin sensitivity. The team says that the technique could be useful for a wide range of cryogenic studies of the thermal properties of surfaces having nanoscale structures.

Understanding and controlling heat flow through materials is essential for developing a wide range of technologies. For example, researchers have begun to use two-dimensional materials, such as graphene, cooled to cryogenic temperatures, to conduct heat away from hot spots in microelectronic devices. In these materials and at these low temperatures, heat can travel long distances without dissipation, which makes these materials extremely effective heat conductors. However, the precise mechanisms for this heat transport are still poorly understood. More generally, researchers would also like to better understand other anomalous thermal properties of materials that apply at these temperatures, such as a regime where heat flows as waves.

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Petr Šulc, an assistant professor at Arizona State University’s School of Molecular Sciences, worked with Professor Michael Famulok from the University of Bonn, Germany, and Professor Nils Walter from the University of Michigan on this project.