A method of analyzing a molecule, the method comprising: forming a lipid bilayer that divides a first reservoir from a second reservoir, wherein the first reservoir has a first reservoir osmolarity, and wherein the second reservoir has a second reservoir osmolarity; characterized in that it further comprises: flowing an electrolyte solution to the first reservoir, wherein the electrolyte solution has an electrolyte solution osmolarity that differs from the first reservoir osmolarity, thereby making a first change to a ratio of the first reservoir osmolarity to the second reservoir osmolarity; and applying a voltage across the lipid bilayer, wherein the lipid bilayer includes a nanopore that preferentially conducts either anions or cations and has unequal conductivity under positive and negative electrical bias, and wherein the voltage causes a net transfer of ions between the first reservoir and the second reservoir, thereby making a second change to the ratio of the first reservoir osmolarity to the second reservoir osmolarity, wherein the first change to the ratio and the second change to the ratio substantially counterbalance each other, wherein the voltage applied across the lipid bilayer is an alternating current voltage. forming a lipid bilayer that divides a first reservoir from a second reservoir, wherein the first reservoir has a first reservoir osmolarity, and wherein the second reservoir has a second reservoir osmolarity; characterized in that it further comprises: flowing an electrolyte solution to the first reservoir, wherein the electrolyte solution has an electrolyte solution osmolarity that differs from the first reservoir osmolarity, thereby making a first change to a ratio of the first reservoir osmolarity to the second reservoir osmolarity; and applying a voltage across the lipid bilayer, wherein the lipid bilayer includes a nanopore that preferentially conducts either anions or cations and has unequal conductivity under positive and negative electrical bias, and wherein the voltage causes a net transfer of ions between the first reservoir and the second reservoir, thereby making a second change to the ratio of the first reservoir osmolarity to the second reservoir osmolarity, wherein the first change to the ratio and the second change to the ratio substantially counterbalance each other, wherein the voltage applied across the lipid bilayer is an alternating current voltage. flowing an electrolyte solution to the first reservoir, wherein the electrolyte solution has an electrolyte solution osmolarity that differs from the first reservoir osmolarity, thereby making a first change to a ratio of the first reservoir osmolarity to the second reservoir osmolarity; and applying a voltage across the lipid bilayer, wherein the lipid bilayer includes a nanopore that preferentially conducts either anions or cations and has unequal conductivity under positive and negative electrical bias, and wherein the voltage causes a net transfer of ions between the first reservoir and the second reservoir, thereby making a second change to the ratio of the first reservoir osmolarity to the second reservoir osmolarity, wherein the first change to the ratio and the second change to the ratio substantially counterbalance each other, wherein the voltage applied across the lipid bilayer is an alternating current voltage.