The automated internal perfusion is also applicable for planar lipid bilayer recordings. Giant unilamellar vesicles (GUVs) were used for bilayer formation on the chips and gramicidin currents were recorded. In a situation with multiple gramicidin channels being active, solutions with different conductivity (high: 0.1M HCl and low: 0.1M KCl) were exchanged repetitively. The single channel current amplitudes are increased/decreased respectively. This way, the perfusion time constants can be measured and typically are in the range of 1-2 seconds. These experiments also show the high stability of the miniature bilayers upon perfusion.