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Nonreciprocal Interactions Go Nonlinear: How Nanoparticles Are Changing the Rules of Physics

Using two optically trapped glass nanoparticles, researchers observed a novel collective Non-Hermitian and nonlinear dynamic driven by nonreciprocal interactions. This contribution expands traditional optical levitation with tweezer arrays by incorporating the so-called non-conservative interactions. Their findings, supported by an analytical model developed by collaborators from Ulm University and the University of Duisburg-Essen, were recently published in Nature Physics.

Understanding Nonreciprocal Interactions

Fundamental forces like gravity and electromagnetism are reciprocal, meaning two objects either attract or repel each other. However, for some more complex interactions arising in nature, this symmetry is broken and some form of nonreciprocity exists. For example, the interaction between a predator and a prey is inherently nonreciprocal as the predator wants to catch (is attracted to) the prey and the latter wants to escape (is repelled).

Self-powered electrostatic tweezer for adaptive object manipulation and microfluidics

In a study published in Device (“Self-powered electrostatic tweezer for adaptive object manipulation”), a research team led by Dr. DU Xuemin from the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences has reported a new self-powered electrostatic tweezer that offers superior accumulation and tunability of triboelectric charges, enabling unprecedented flexibility and adaptability for manipulating objects in various working scenarios.

The ability to manipulate objects using physical tweezers is essential in fields such as physics, chemistry, and biology. However, conventional tweezers often require complex electrode arrays and external power sources, have limited charge-generation capabilities, or produce undesirable temperature rises.

The newly proposed self-powered electrostatic tweezer (SET) features a polyvinylidene fluoride trifluoroethylene (P(VDF-TrFE))-based self-powered electrode (SE) that generates large and tunable surface charge density through the triboelectric effect, along with a dielectric substrate that functions as both a tribo-counter material and a supportive platform, and a slippery surface to reduce resistance and biofouling during object manipulation.

17th Century Sunspot Drawings Could Help Solve 400-Year-Old Solar Cycle Mystery

“Kepler contributed many historical benchmarks in astronomy and physics in the 17th century, leaving his legacy even in the space age,” said Hisashi Hayakawa.


How can 400-year-old sunspot drawings help modern-day scientists with solar cycles? This is what a recent study published in The Astrophysical Journal Letters hopes to address as an international team of researchers used 400-year-old drawings of sunspots to better understand solar cycles and how we can study them in the future. This study holds the potential to help researchers use non-electronic scientific tools to gain greater insight into scientific discoveries around the world.

For the study, the researchers examined drawings of sunspots made by Johannes Kepler in 1,607 along with past notes to ascertain which solar cycle these sunspots belonged to, which could help astronomers piece together solar cycles during that time and predict them, as well.

Cosmic Simulation Reveals How Black Holes Grow and Evolve

A team of astrophysicists led by Caltech has managed for the first time to simulate the journey of primordial gas dating from the early universe to the stage at which it becomes swept up in a disk of material fueling a single supermassive black hole. The new computer simulation upends ideas about such disks that astronomers have held since the 1970s and paves the way for new discoveries about how black holes and galaxies grow and evolve.

“Our new simulation marks the culmination of several years of work from two large collaborations started here at Caltech,” says Phil Hopkins, the Ira S. Bowen Professor of Theoretical Astrophysics.

The first collaboration, nicknamed has focused on the larger scales in the universe, studying questions such as how galaxies form and what happens when galaxies collide. The other, dubbed STARFORGE, was designed to examine much smaller scales, including how stars form in individual clouds of gas.

Escaping kinetic traps: How molecular interactions make it possible to overcome the energy barrier

In a paper in Physical Review Letters scientists from the department Living Matter Physics at the Max Planck Institute for Dynamics and Self-Organization (MPI-DS) propose a mechanism on how energy barriers in complex systems can be overcome. These findings can help to engineer molecular machines and to understand the self-organization of active matter.