It’s a centuries-old problem: how to prepare the perfect slice of toast. Historical toasters range from a simple iron frame standing slices of bread in front of a hearth to Rube Goldberg-like contraptions of springs and knobs that turn, flip and eject.
The core technology of the toaster has changed little in the past 100 years. A coil of high-resistance wires is activated for a certain period, and the radiant heat from that coil warms and browns the bread. The only measure of doneness that a traditional toaster has is time, but, as anyone who has had burnt toast for breakfast knows, time is a very imprecise proxy.
