Internet
Researchers at Pohang University of Science and Technology (POSTECH) have advanced online security by integrating an AI-based metasurface with oblique helicoidal cholesteric liquid crystals.
Apr 15, 2024
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21
Hardware
Imagine being able to build an entire dialysis machine using nothing more than a 3D printer.
Feb 23, 2024
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44
Robotics
"Soft robots," medical devices and implants, and next-generation drug delivery methods could soon be guided with magnetism—thanks to a metal-free magnetic gel developed by researchers at the University of Michigan and the ...
Jan 16, 2024
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69
Energy & Green Tech
An increasing number of electric cars are being sold, consequently raising the quantity of produced electric motors. At the end of their useful life, these electric motors are shredded and then recycled. The individual components ...
Jan 2, 2024
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15
Engineering
3D-stacked electronics made of interconnected vertical layers of chips are the next generation in energy efficient high-performance devices.
Sep 13, 2023
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1
Electronics & Semiconductors
Random Telegraph Noise (RTN), a type of unwanted electronic noise, has long been a nuisance in electronic systems, causing fluctuations and errors in signal processing. However, a team of researchers from the Center for Integrated ...
Aug 10, 2023
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114
Engineering
Excess heat from electronic or mechanical devices is a sign or cause of inefficient performance. In many cases, embedded sensors to monitor the flow of heat could help engineers alter device behavior or designs to improve ...
Jul 24, 2023
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72
Engineering
Human skin is amazing. It senses temperature, pressure, and texture. It's able to stretch and spring back, time and again. And it provides a barrier between the body and external threats—bacteria, viruses, toxins, ultraviolet ...
Jun 1, 2023
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58
Engineering
Metasurfaces, two-dimensional (2D) or planar versions of metamaterials exhibit properties that are not typically found in natural materials. As they are flat, these materials can typically be produced using widely known fabrication ...
Engineering
Superconductors make highly efficient electronics, but the ultralow temperatures and ultrahigh pressures required to make them work are costly and difficult to implement. Room-temperature superconductors promise to change ...
Mar 28, 2023
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A magnet (from Greek μαγνήτις λίθος magnḗtis líthos, "Magnesian stone") is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials and attracts or repels other magnets.
A permanent magnet is one made from a material that stays magnetized. An example is a magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include iron, nickel, cobalt, some rare earth metals and some of their alloys (e.g. Alnico), and some naturally occurring minerals such as lodestone.
Although ferromagnetic (and ferrimagnetic) materials are the only ones with an attraction strong enough to a magnet to be commonly considered "magnetic", all other substances respond weakly to a magnetic field, by one of several other types of magnetism.
An electromagnet is made from a coil of wire which acts as a magnet when an electric current passes through it, but stops being a magnet when the current stops. Often an electromagnet is wrapped around a core of ferromagnetic material like steel, which enhances the magnetic field produced by the coil.
The overall strength of a magnet is measured by its magnetic moment, while the local strength of the magnetism in a material is measured by its magnetization.
This text uses material from Wikipedia, licensed under CC BY-SA
