Memristors are electrical resistors with memory—advanced electronic devices that regulate current based on the history of the voltages applied to them. They can store and process data simultaneously, making them much more efficient than traditional systems. They could enable new platforms that process many signals in parallel and are capable of advanced machine learning. The memristor is a good model for a synapse. It mimics how the connections between neurons strengthen or weaken when signals pass through them. But the changes in conductance typically come from changes in the shape of the channels of conductive material within the memristor. These channels—and the memristor’s ability to conduct electricity—could not be precisely controlled in previous devices.