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Category: engineering

No Free Lunch for Sound Waves

Sound wave scattering can be increased in one frequency range only by reducing scattering in another range, according to experiments—a discovery relevant for acoustic engineering.

Acoustic metamaterials allow blocking, absorbing, or redirecting waves in ways not possible with conventional materials. Now researchers have shown that all such structures face a previously unrecognized constraint: The total acoustic scattering is fixed, so that boosting scattering in one frequency band necessarily depletes it elsewhere [1]. This general restriction provides a new way of thinking about how acoustic performance can be optimized, which could guide the design of broadband sound-control devices, from noise barriers to acoustic cloaks.

By building structures into materials on length scales smaller than the wavelength of sound, researchers can create artificial resonant elements that interact strongly with acoustic waves. Such structures can produce effects that are difficult or impossible to achieve otherwise—for example, strong sound attenuation through thin material layers. Such advances have led to new techniques for lightweight soundproofing and sound steering.

Out-of-plane ice bridges reveal new way to suppress frost spreading

A research team led by Professor Nenad Miljkovic in The Grainger College of Engineering at the University of Illinois Urbana-Champaign has published a breakthrough study in Nature Physics. The work reports the first experimental discovery of a previously unknown frost propagation mechanism—a “suspended ice bridge”—offering new pathways for anti-frosting surface design.

Frost formation plays a critical role in many engineering systems, including air-source heat pumps, refrigeration systems and aerospace applications. At the microscopic level, frost mainly spreads through the formation of “ice bridges” that connect neighboring supercooled liquid droplets, enabling freezing to propagate rapidly across a surface. For decades, these ice bridges were widely assumed to grow along the solid surface.

This assumption, largely based on conventional top-view imaging, has shaped existing theoretical models and anti-frosting strategies. However, the Illinois team’s study reveals that this long-held view is incomplete.

Nanomagnets control diamond qubits, pointing to more scalable quantum hardware

Quantum computing, once only a theoretical possibility, promises to deliver faster, more energy-efficient computers—but only if scientists can build and scale the hardware needed to run the machines. New research from Virginia Commonwealth University brings scientists one small step closer to quantum computing at a practical scale, which could help dramatically reduce energy usage and computing times in some industries.

In the study, recently published in Nature Communications, the researchers used minuscule magnets—twice as small as the wavelength of light—to create the building blocks of quantum computing, pioneering a technique that could decrease the physical space needed to create a viable quantum computer.

“This work has the potential to advance quantum computing,” said Jayasimha Atulasimha, Ph.D., a professor of mechanical and nuclear engineering in VCU’s College of Engineering and the study’s principal investigator. “We’re solving a specific problem for spin-based quantum computing, which has the potential for scaling.”

John Nash (1928−2015)

John Nash was born on June 13, 1928, in Bluefield, West Virginia, a former coal town nestled deep in the Appalachian Mountains. As a young boy, Nash was solitary, bookish, and introverted. His father, John Sr., was a quiet engineer with an incisive mind. His mother, Virginia, also intelligent, was a former teacher who had large dreams for her son, pushing him to read at four, learn Latin, and skip a grade at school.

The first hint of John Nash’s math talent came in fourth grade, when a teacher told Virginia that the boy couldn’t do the math. Virginia laughed, well aware that her son was going down his own path to solve the simple problems. In high school, John solved his teachers’ clunky proofs in just a few elegant steps. He was one of ten nationally awarded winners of the George Westinghose Award, which provided him with a full scholarship to the Carnegie Institute of Technology. He hopped from engineering to chemistry before discovering his passion: mathematics.

He was accepted into Princeton University, which at the time was to mathematicians what Detroit was, and still is, to cars. Nash first wowed his peers with an elegantly playable board game, which his peers dubbed “Nash,” but later reached the market as Hex. He then absorbed himself in one of the sexiest math fields of the day, game theory, which described strategies in competition, whether in card games or business. His deceptively simple doctoral thesis would later re-orient the field of economics, although no one, not even Nash, predicted its potential.

Axial encoding unlocks up to eightfold faster 3D microscopy with less light

A research team from HKU Engineering has pioneered a fundamentally new imaging strategy known as AIMED (Arbitrary illumination microscopy with encoded depth), which utilizes a sub-sampling approach. By integrating innovations in axial optical encoding with advanced computational image reconstruction, the AIMED technology enables a substantial increase in 3D imaging speed while enhancing photon safety, all with minimal additional system complexity. This breakthrough demonstrates significant advantages across efficiency, image quality, and system compatibility.

This work was conducted by the OMEGA laboratory under the leadership of Professor Kenneth K. Y. Wong of the Department of Electrical and Computer Engineering at the University of Hong Kong (HKU). The study is published in the journal Advanced Photonics.

Toward cheaper, cleaner hydrogen production

Sobek was born and raised in Argentina, but he also grew up at MIT over the course of three degrees and more than a decade. He first studied aeronautics and astronautics at MIT, then jumped to mechanical engineering as a graduate student, then moved to the Department of Electrical Engineering and Computer Science, where he worked under PhD advisors and MIT professors Martha Gray and Stephen Senturia. His thesis focused on a technique for quickly measuring optical properties of large numbers of biological cells.

“A lot of my learnings around microfabrication and materials chemistry ended up being really relevant for 1s1,” Sobek says. “A class that was very important to me was taught by Professor Amar Bose. I was a teaching assistant for him for a couple of semesters, and that had an incredible influence on my thinking.”

Following graduation, Sobek worked in microelectronics and microfluidics before founding his own company, Zymera, in 2004. The company developed deep-tissue imaging technology for detecting cancer and other serious diseases.

Nanofiber implant delivers three drugs, doubles survival in glioblastoma mice

Researchers with the University of Cincinnati and Johns Hopkins Medicine developed a potential treatment for brain cancer that uses nanofibers embedded with a combination of drugs that work in concert to target tumors. The drugs proved more effective in combination than when administered alone and can provide both immediate and long-lasting doses to kill cancer cells.

“In our study, a three-drug combination showed strong synergistic effects across multiple glioblastoma models and significantly improved survival in animal studies,” said Daewoo Han, an assistant professor in UC’s College of Engineering and Applied Science and lead author of the paper published in ACS Biomaterials Science & Engineering.

Han and Distinguished Research Professor Andrew Steckl incorporated the drugs into electrospun fiber membranes, creating a nanofiber drug delivery system. Steckl’s NanoLab at the University of Cincinnati is a leading developer of this technology that uses an electric field to create a multilayered fiber mesh for drug delivery, among other uses. “This combination is pretty powerful,” Steckl said.

A Symbolic Analysis of Relay and Switching Circuits

In 1937, a young graduate student named Claude Shannon submitted a master’s thesis with an unassuming title: “A Symbolic Analysis of Relay and Switching Circuits.”

A Symbolic Analysis of Relay and Switching Circuits is the title of a master’s thesis written by computer science pioneer Claude E. Shannon while attending the Massachusetts Institute of Technology (MIT) in 1937, [ 1 ] [ 2 ] and then published in 1938. In his thesis, Shannon, a dual degree graduate of the University of Michigan, proved that Boolean algebra [ 3 ] could be used to simplify the arrangement of the relays that were the building blocks of the electromechanical automatic telephone exchanges of the day. He went on to prove that it should also be possible to use arrangements of relays to solve Boolean algebra problems. His thesis laid the foundations for all digital computing and digital circuits. [ 4 ] [ 5 ]

The utilization of the binary properties of electrical switches to perform logic functions is the basic concept that underlies all electronic digital computer designs. Shannon’s thesis became the foundation of practical digital circuit design when it became widely known among the electrical engineering community during and after World War II. At the time, the methods employed to design logic circuits (for example, contemporary Konrad Zuse’s Z1) were ad hoc in nature and lacked the theoretical discipline that Shannon’s paper supplied to later projects.

Shannon’s work also differed significantly in its approach and theoretical framework compared to the work of Akira Nakashima. Whereas Shannon’s approach and framework was abstract and based on mathematics, Nakashima tried to extend the existent circuit theory of the time to deal with relay circuits, and was reluctant to accept the mathematical and abstract model, favoring a grounded approach. [ 6 ] Shannon’s ideas broke new ground, with his abstract and modern approach dominating modern-day electrical engineering. [ 6 ].

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