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, a first left branch, and a first right branch formed in the membrane, the first left and right branches being connected to the first stem at a first junction;
• wherein the second Y-channel includes a second stem, a second left branch, and a second right branch formed in the membrane, the second left and right branches being connected to the second stem at a second junction, wherein the second stem of the second Y-channel is connected to the first left branch of the first Y-channel such that the first left branch feeds into the second Y-channel, and wherein the second junction comprises a sharp end configured to separate baase pairs;
• 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;
• and
• driving the double strand molecule into the sharp end of the second junction to thereby split the double strand molecule into the first single strand and the second single strand using a second voltage pulse.