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A class of synthetic soft materials called liquid crystal elastomers (LCEs) can change shape in response to heat, similar to how muscles contract and relax in response to signals from the nervous system. 3D printing these materials opens new avenues to applications, ranging from soft robots and prosthetics to compression textiles.

Controlling the material’s properties requires squeezing this elastomer-forming ink through the of a 3D printer, which induces changes to the ink’s internal structure and aligns rigid building blocks known as mesogens at the molecular scale. However, achieving specific, targeted alignment, and resulting properties, in these shape-morphing materials has required extensive trial and error to fully optimize printing conditions. Until now.

In a new study, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), Princeton University, Lawrence Livermore National Laboratory, and Brookhaven National Laboratory worked together to write a playbook for printing liquid crystal elastomers with predictable, controllable alignment, and hence properties, every time.

An Oregon State University researcher has helped create a new 3D printing approach for shape-changing materials that are likened to muscles, opening the door for improved applications in robotics as well as biomedical and energy devices.

The liquid crystalline elastomer structures printed by Devin Roach of the OSU College of Engineering and collaborators can crawl, fold and snap directly after printing. The study is published in the journal Advanced Materials.

“LCEs are basically soft motors,” said Roach, assistant professor of mechanical engineering. “Since they’re soft, unlike regular motors, they work great with our inherently soft bodies. So they can be used as implantable medical devices, for example, to deliver drugs at targeted locations, as stents for procedures in target areas, or as urethral implants that help with incontinence.”

The fundamental principles of thermodynamics have long been a cornerstone of our understanding of the physical world, with the second law of thermodynamics standing as a testament to the inexorable march towards disorder and entropy that governs all closed systems. However, the realm of quantum physics has traditionally appeared to defy this notion, with mathematical formulations suggesting that entropy remains constant in these systems.

Recent research has shed new light on this seeming paradox, revealing that the apparent contradiction between quantum mechanics and thermodynamics can be reconciled through a nuanced understanding of entropy itself. By adopting a definition of entropy that is compatible with the principles of quantum physics, specifically the concept of Shannon entropy, scientists have demonstrated that even isolated quantum systems will indeed evolve towards greater disorder over time, their entropy increasing as the uncertainty of measurement outcomes grows.

This breakthrough insight has far-reaching implications for our comprehension of the interplay between quantum theory and thermodynamics, and is poised to play a pivotal role in the development of novel quantum technologies that rely on the manipulation of complex many-particle systems.

Using levitating nanospheres trapped in laser beams, they can observe how matter behaves in ways never seen before. This breakthrough could help unravel the mysteries of the quantum world.

Exploring the Boundary Between Classical and Quantum Worlds

A recent study published in the scientific journal Optica introduces a groundbreaking experimental device that bridges the gap between classical and quantum physics. This innovative instrument enables researchers to observe and study phenomena from both realms simultaneously. Developed in Florence, the device is the result of a collaborative effort within the National Quantum Science and Technology Institute (NQSTI). It involves experts from the University of Florence’s Department of Physics and Astronomy, the National Institute of Optics (CNR-INO), the European Laboratory for Nonlinear Spectroscopy (LENS), and the Florence branch of the National Institute for Nuclear Physics (INFN).

An experiment in Sweden has demonstrated control over a novel kind of magnetism, giving scientists a new way to explore a phenomenon with huge potential to improve electronics – from memory storage to energy efficiency.

Using a device that accelerates electrons to blinding speeds, a team led by researchers from the University of Nottingham showered an ultra-thin wafer of manganese telluride with X-rays of different polarizations, to reveal changes on a nanometer scale reflecting magnetic activity unlike anything seen before.

For a rather mundane chunk of iron to transform into something a little more magnetic, its constituent particles need to be arranged so that their unpartnered electrons align according to a property known as spin.