Discovered Materials' Akash Ramdas breaks down why copper has hit a physics-based limit for chips: "We all learn resistors, how they prevent current flow, and we always learn there is a specific resistance, so every material has a specific resistance value. But that's not exactly precisely true." "As you scale down, the surfaces also contribute to limiting the flow of current in devices. If you thin copper beyond a certain thinness, you end up having a very high specific resistivity. So there's almost a physics-based limit that copper can't overcome anymore." "There's a similar picture for the mobility of silicon. Beyond a certain thinning of the silicon, it has the same issues. So there are physical limits to the current materials, and a lot of our progress has been finding ways to work around those limits and still achieve improvements in performance." "New materials could fundamentally redefine what those limits are."