Explaining Hall-effect, TMR, and other new types of "mechanical" switches

Ars Technica has published a comprehensive guide to new keyboard sensing technologies, including Hall-effect, TMR, and other types of mechanical switches. Hall-effect switches use a magnetic field to detect switch actuation, while TMR (tunnel magnetoresistance) switches rely on the change in magnetic resistance when a current flows through a thin layer of material. Other types of switches mentioned include capacitive and optical switches. The article goes into detail about how these technologies work, their advantages, and the companies that are using them in their keyboards. Some examples of keyboards that use these technologies include the Logitech G Pro X and the Razer BlackWidow Lite, which use Hall-effect switches, and the Anne Pro 2, which uses TMR switches. The article also discusses the potential benefits and drawbacks of these new technologies, including improved durability and precision, but also potential issues with reliability and cost.