Mechanical Engineering: Research Guide

Micro-electro-mechanical devices (MEMS) are based on the integration of mechanical and electrical components on a micrometer scale. We all use them continuously in our everyday life: For example, in our mobile phones there are at least a dozen MEMS that regulate different activities ranging from motion, position, and inclination monitoring of the phone; active filters for the different transmission bands, and the microphone itself.

Alkaline fuel cells (AFC) convert the chemical energy of hydrogen and oxygen into electrical energy, while only producing water as a by-product. This makes them an extremely attractive next generation, environmentally friendly energy source. Although platinum catalysts are generally employed in alkaline fuel cells, they are expensive and also experience challenges related to stability when used in alkaline fuel cells. As a result, single-atom catalysts (SACs), as formed on carbon supports, are becoming promising candidates as alternative, next generation catalysts. However, the commercialization of these single-atom catalysts is difficult owing to the complex synthesis methods conventionally..

A team of researchers affiliated with a host of entities in China and one in the U.S. has developed a modified textile that can keep skin cooler than materials made of cotton. In their paper published in the journal Nature Nanotechnology, the group describes their approach to developing garments that are cooler when worn in outdoor conditions.

Global drinking water scarcity is a severe problem for humans. Water purification consumes a large amount of fossil energy and generates secondary pollution.

Researchers in Korea succeeded in developing a core material for the next-generation neuromorphic (neural network imitation) semiconductor for the first time in the country. This is a result of a research team led by Dr. Jung-dae Kwon and Yong-hun Kim of the Department of Energy and Electronic Materials of the Korea Institute of Materials Science, together with Professor Byungjin Cho's research team at Chungbuk National University. KIMS is a government-funded research institute under the Ministry of Science and ICT.

Scientists at St Petersburg University, Sirius University of Science and Technology, and St Petersburg Academic University have synthesized the smallest nano-sized metal-organic frameworks to detect heavy metal ions in water. The results and outcomes of the experiments and description of the properties of the crystals are published in Nanomaterials.

For some, the mere mention of liquid metal might conjure visions of T-1000: the shapeshifting, nigh-invincible villain that turns up the heat on humanity's future savior in "Terminator 2."

Scientists in Australia have used tin mono-sulfide (SnS) nanosheets to create the thinnest X-ray detector ever made, potentially enabling real-time imaging of cellular biology.

Fluorescent "dots"—that is, tiny particles that can emit light—have a multitude of promising biomedical applications, from helping clinicians to better identify tumor margins to delivering a drug deep in the body. However, making such dots is usually a long and tedious process that uses harsh chemicals. Now, NIBIB-funded researchers are developing a fluorescent dot that is not only easier to make, but uses environmentally friendly materials.

Recently, researchers developed high-performance solar thermal copper sulfide photothermal ink and photothermal film, marking big progress in the field of Plasmonic Solar photothermal Materials.

In a new publication from Opto-Electronic Advances, Shreeniket Joshi and Amirkianoosh Kiani from Ontario Tech University, Ontario, Canada, discuss hybrid artificial neural networks and analytical model for prediction of optical constants and bandgap energy of 3D nanonetwork silicon structures.

Researchers have developed a technique whereby they can spontaneously encapsulate microscopic droplets of water and oil emulsion in a tiny sphere made of salt crystals—sort of like a minute, self-constructing origami soccer ball filled with liquid. The process, which they are calling 'crystal capillary origami,' could be used in a range of fields from more precise drug delivery to nanoscale medical devices. The technique is described in a paper appearing in the journal Nanoscale on September 21.

As a crucial part of spectrum analysis, solar-blind ultraviolet photodetectors (SBPDs) are applied to many fields. Because of their specialized applications, they have to cope with harsh environments such as overabundant temperature and radiation. Therefore, a substitute for traditional silicon-substrate SBPDs is needed.

Murky green algal blooms are more than a major eyesore; they reveal that a body of water could be unsafe for swimming or drinking. Currently, however, there isn't an effective warning system for impending blooms. Now, researchers in ACS Applied Nano Materials report an indicator that changes color when exposed to rising levels of alkaline phosphatase—an enzyme that forecasts phytoplankton's exponential growth. This change can be detected by the naked eye or a smartphone.

Liquid crystals already provide the basis for successful technologies like LCD displays, and researchers continue to create specific kinds of liquid crystals for even better optical devices and applications.

The potential of DNA structural properties in single-molecule electronics has finally been harnessed by researchers from Tokyo Institute of Technology (Tokyo Tech) in a single-molecule junction device that shows spontaneous self-restoring ability. Additionally, the device, based on a "zipper" DNA configuration, shows unconventionally high electrical conductivity, opening doors to the development of novel nanoelectronic devices.

In the last few years, a class of materials called antiferroelectrics has been increasingly studied for its potential applications in modern computer memory devices. Research has shown that antiferroelectric-based memories might have greater energy efficiency and faster read and write speeds than conventional memories, among other appealing attributes. Further, the same compounds that can exhibit antiferroelectric behavior are already integrated into existing semiconductor chip manufacturing processes.

The thinnest materials in the world are only a single atom thick. These kinds of two-dimensional or 2D materials—such as graphene, well-known as consisting of a single layer of carbon atoms—are causing a great deal of excitement among research teams worldwide. This is because these materials promise unusual properties that cannot be obtained using three-dimensional materials. As a result, 2D materials are opening the door to new applications in fields such as information and display technology, as well as for critical components in extremely sensitive sensors.

Acollaborated team led by Prof. Su Fuhai from the Hefei Institutes of Physical Science (HFIPS)of the Chinese Academy of Sciences (CAS) recently identified the ultrafast dynamics in monolayer MoS2/ReSe2heterostructures.

From a team of City College of New York physicists and their collaborators in Japan and Germany comes another advancement in the study of excitons—electrically neutral quasiparticles that exist in insulators, semi-conductors and some liquids. The researchers have created an "excitonic" wire, or one-dimensional channel for excitons. This resulting devices could one day replace certain tasks that are now performed by standard transistor technology.

The device you are currently reading this article on was born from the silicon revolution. To build modern electrical circuits, researchers control silicon's current-conducting capabilities via doping, which is a process that introduces either negatively charged electrons or positively charged "holes" where electrons used to be. This allows the flow of electricity to be controlled and for silicon involves injecting other atomic elements that can adjust electrons—known as dopants—into its three-dimensional (3D) atomic lattice.

Flip through any chemistry textbook and you'll see drawings of the chemical structure of molecules—where individual atoms are arranged in space and how they're chemically bonded to each other. For decades, chemists could only indirectly determine chemical structures based on the response generated when samples interacted with x-rays or particles of light. For the special case of molecules on a surface, atomic force microscopy (AFM), invented in the 1980s, provided direct images of molecules and the patterns they form when assembling into two-dimensional (2D) arrays. In 2009, significant advances in high-resolution AFM (HR-AFM) allowed chemists for the first time to directly image the chemi..

When two layers of graphene or of other two-dimensional (2D) materials are stacked on top of each other with a small angle misalignment, the crystal lattices produced by each layer are spatially 'out of synch'. This results in a unique structural pattern known as moiré superlattice.

Cracked phone screens could become a thing of the past thanks to breakthrough research conducted at The University of Queensland.

Phononic crystals (PnCs) are artificial structural composites with periodic modulation of elastic parameters, andthey are capable of regulating the propagation of sound waves. Devices with different geometric parameters have been made to regulate phonon band structure. However, how to achieve field adjustment of band structure remains a challenge.

Twisted bilayer graphene is a carbon-based, two-dimensional (2D) material comprising two graphene layers. Although many scientists have recently started exploring its potential for superconductivity and magnetism, so far, there have been very few optical studies examining it.

Oil and water do not mix, but what happens where oil and water meet? Or where air meets liquid? Unique reactions occur at these interfaces, which a team of researchers based in Japan used to develop the first successful construction of uniform, electrically conductive nanosheets needed for next-generation sensors and energy production technologies.