Nonlinear conduction in bilayer lipid membranes – effect of temperature

We present here our investigation on the effect of temperature on the reversible nonlinearity as manifested in the DC I–V characteristic of bilayer lipid membrane (BLM). Vc and Ic, the values of voltage and current at the onset of nonlinearity, have been found to be functions of temperature, and the nonlinearity has been found to decrease with increase in temperature. By proper scaling of voltage and current by Vc and Ic, respectively, the I–V curves taken at different temperatures collapse into one single curve, showing the universality in their nature. A log–log plot of Ic vs. σ0 (linear conductance) is a straight line where Ic scales with σ0 as Ic σ01.56. A possible mode of charge conduction in BLM, which is a disordered composite system of lipid and water molecules, has been proposed on the basis of these experimental results.