Localized Joule heating produced by ion current focusing through micron-size holes

摘要

We provide an experimental demonstration that the focusing of ionic currents in a micron size hole connecting two chambers can produce local temperature increases of up to 100℃ with gradients as large as 1 °K μn~(-1). We find a good agreement between the measured temperature profiles and a finite elements-based numerical calculation. We show how the thermal gradients can be used to measure the full melting profile of DNA duplexes within a region of 40 μm. The possibility to produce even larger gradients using submicron pores is discussed.