Base-by-base ratcheting of DNA/RNA in a Y-shaped nanochannel

A method for ratcheting a double strand molecule, the method comprising:

• driving the double strand molecule into a first Y-channel and a second Y-channel of a membrane by a first voltage pulse, the first Y-channel includes a first stem and first branches, the first branches being connected to the first stem at a first junction;
• wherein the second Y-channel includes a second stem and second branches formed in the membrane, the second branches being connected to the second stem at a second junction, wherein at least one of the second branches of the second Y-channel is connected to at least one of the first branches of the first Y-channel such that one or more of the first branches feeds into the second Y-channel;
• slowing the double strand molecule at the first junction of the first Y-channel based on the first voltage pulse being weaker than a force required to break a base pair of the double strand molecule;
• splitting the double strand molecule into a first single strand and a second single strand by driving the double strand molecule into the first junction of the first Y-channel at a second voltage pulse;
• and
• reversing a direction of the double strand molecule through the membrane by discontinuing the first voltage pulse and the second voltage pulse.