Mechanical Engineering: Research Guide

Hydrogen could play an important role in cleaner energy systems, but even small leaks can create safety risks. Reliable sensors are therefore essential wherever hydrogen is produced, stored, transported or used. A persistent problem is humidity: water molecules can cover the active surfaces of hydrogen detectors and prevent them from responding accurately, particularly in hot, moisture-rich environments.

In 1974, the University of Melbourne's chemistry professor Richard Robson had the idea of replacing the wooden balls and metal rods used in structural models with molecules and chemical bonds. He began experimenting with copper ions linked by a four-armed organic molecule, creating a structure with a cavity. His work laid the foundation for metal–organic frameworks (MOFs), a class of porous materials formed by linking metal ions with organic molecules. Their pores can capture pollutants, support chemical reactions and store gases, giving MOFs a wide range of potential applications.

Building an accurate model of how atoms interact is a complicated process. Researchers must choose new calculations, test successive models and track the mechanisms behind each interaction. But a newly developed AI agent called MLP Copilot has made this process much easier by bridging computational tools and scientific evidence with human supervision.

Researchers at the University of Rochester and Technion–Israel Institute of Technology accidentally discovered a new way to rearrange the internal structure of molybdenum—an extremely heat-resistant metal—at room temperature. Molybdenum is typically used to reinforce nuclear reactors, jet engine turbine blades and rocket nozzles because it doesn't melt until it is heated to more than 2,600°C (4,712°F). Controlling its atomic structure at room temperature could open the door to more applications, including next-generation semiconductors.

Helicenes are a class of organic molecules consisting of benzene rings arranged in a spiral-like shape. These molecules exhibit significant circularly polarized luminescence—emission of light with left or right handedness—and are expected to be utilized in 3D displays and anti-counterfeiting inks. Carbohelicenes, a subgroup of helicenes, are composed entirely of carbon and hydrogen.

Penn State researchers have refined an atom-scale model of how silicon carbide changes from a solid into vapor during crystal growth, work that could help manufacturers produce higher-quality material for advanced electronics while reducing costly trial-and-error experiments.

Nanographenes with up to eight helicene units can now be selectively synthesized using a two-step process. Researchers from Science Tokyo have developed a strategy to synthesize multi-helical nanographenes containing up to eight helicene units with controlled handedness.

Researchers revealed an ultralow-barrier collective sliding mechanism mediated by domain walls, as well as defect-induced pinning of the sliding motion. They found that twisted bilayer MoS₂ moiré superlattices can undergo spontaneous long-range interlayer sliding at room temperature, while a sulfur-vacancy concentration of only about 0.1% can turn the motion into localized oscillations.

Fluorescent materials usually emit a single consistent color. They are typically made from dyes or metallic components. In contrast, researchers reporting in ACS Central Science have created carbon dots that can fluoresce in a range of colors under UV light, depending on the concentration and the liquid they're in. The team incorporated the new carbon dots into plastic decorations and used them to create a data encryption system.

Dewetting of thin films is a phenomenon in which heat or laser irradiation destabilizes a continuous film, causing it to retract into nanoscale island-like structures. Compared to thermal dewetting, laser-induced dewetting offers greater precision, speed and flexibility and is a promising approach for patterning metallic thin films.

Creating better-performing materials comes down to having more control over their structure at the smallest possible scale. One particularly effective way to accomplish that is using nanoparticles, which have highly customizable shapes and sizes and have already shown promise in applications across energy, medicine and electronics.

Colors in nature are not always produced by pigments. Pearls, bird feathers, butterfly wings and opals display brilliant colors through the interaction of light with microscopic structures, a phenomenon known as structural color.

A window can admit welcome daylight but also let in unwanted heat, taxing air conditioning systems. Darkening the glass helps control glare, but the absorption of sunlight warms it. An ideal window would block more incoming heat while also letting trapped heat escape.

When you think about making computer chips better, you probably think about transistors. My colleagues and I focused on a less visible part of the problem: the components that deliver power to those transistors. A chip needs more than electricity. It needs electricity supplied at the right voltage, with fluctuations kept under control. Making the hardware that does this smaller is an important challenge—and one that led my colleagues and me to build tiny magnetic devices called stripline microinductors.

New membrane technology delivering faster and more precise molecule separation could improve the efficiency and sustainability of energy-intensive industrial processes—from purifying chemicals and recovering valuable resources to producing sustainable fuels.

With the help of artificial intelligence, researchers at Linköping University in Sweden have found previously overlooked occurrences of the 2D materials MXenes in older databases. The findings have inspired the researchers to create new materials using more sustainable synthesis methods.

As modern electronic devices shrink, so do the metal electrical wires inside them. However, they start to run into serious problems the smaller they get. Conventional wires generate excessive heat and suffer a massive spike in electrical resistance that affects overall performance.

Since the production of graphene in 2004, two-dimensional materials have been sparking scientific and technological interest. As they are only a few atomic layers thick, or even just a single atomic layer, they can exhibit special electronic, magnetic or chemical properties—which make them particularly interesting for applications such as electronics, catalysis and energy storage.

A nano-wrinkled surface combined with a tiny soft actuator can break up infection-causing bacterial sheets, called biofilms, that form on medical implants, according to a University of Michigan Engineering study published in Advanced Functional Materials. When implanted in mice, the platform—called DARTS (dynamically actuated reconfigurable topographical surface)—reduced bacterial burden and improved the surrounding tissue response.

Generating hydrogen without releasing carbon dioxide sounds simple: pass electricity through water, split water molecules and generate green hydrogen. The hard part is the electrocatalyst. The best ones rely on platinum, ruthenium and iridium, which are scarce and expensive. We wanted to know whether a small amount of iron and nickel oxides, anchored on carbon nanofibers grown by chemical vapor deposition the right way on the right scaffold, could do the job instead. Our results are published in ACS Applied Nano Materials.

Metallic materials used in extremely cold environments must maintain high strength, ductility and fracture toughness to support applications in aerospace, clean energy, superconducting systems and deep-space exploration. However, traditional alloys often suffer performance degradation at ultralow temperatures because of the long-standing trade-off between strength, ductility and toughness. Although metals may become stronger at lower temperatures, they can also become more brittle and prone to fracture.

Researchers at AIST have demonstrated the synthesis of nanoporous carbonaceous materials and carbonaceous materials with layered nanostructures through a simple process involving the chemical modification of common sugars such as sucrose and fructose.

Researchers at Umea university thought gold particles would make electronic components emit more light. Instead, they discovered an unexpected effect that could be important for the future of organic electronics.

Molecular machines are regarded as the next step in miniaturization. Their models can be found in living cells, where molecular motors convert energy and generate movement. Scientists have been working for decades to artificially replicate such systems. The 2016 Nobel Prize in Chemistry was awarded for this research.

From photos and videos to documents, vast amounts of data are stored on hard drives in large data centers. These devices use tiny magnetic regions whose orientation determines the information stored. But how could data be stored even faster in the future? One possible approach involves ultrashort laser pulses, which can alter the magnetic order of materials in an extremely short time.

A joint research team fabricated a two-dimensional structure that exhibits properties of both the honeycomb and Kagome lattices using organic molecules. They discovered that edge states specific to topological materials (states that exist only at the edges and are distinct from those in the interior) appear in this structure. The team included researchers from NIMS, Toyota Kosen (National Institute of Technology, Toyota College), Saga University, Nara Women's University, Kiel University (Germany) and other institutions.

New research started with a special material that behaves unusually when it's extremely cold—135 degrees below zero Fahrenheit (minus 93 degrees Celsius), close to the most frigid temperature ever recorded in Antarctica—and showed that the unusual behavior could be extended to well above room temperature—up to about 135 F (57 degrees Celsius), close to the highest heat ever measured in Death Valley, California.

Scientists have long explored the idea of using insects as our agents in the field in places where humans won't fit or survive. Imagine a cockroach in an earthquake zone, able to skitter into the rubble to map out exactly where human chemical signatures can be found, or a grasshopper leaping through a minefield to bring back a map of the bombs based on the vapors it encountered.

It looks like a small, transparent patch with a rainbow on its surface—or for those old enough to remember, the back of a CD. The patch is the first of its kind in the world and, when combined with an ordinary smartphone camera, can measure two things: pulse and blood vessel stiffness.

In a discovery that could offer a new way to control quantum properties in two-dimensional materials, researchers at Cornell have found that electrically sliding the layers of ultrathin graphene can switch the material between distinct magnetic states that persist even after the voltage is removed.