Silicon and Teflon substrates have been structured by wet etching and a focused ion beam (FIB) to obtain very defined, clean apertures. Planar, free-standing lipid membranes (black lipid membranes (BLM)) with enhanced long-term stability have been prepared on these apertures by the methods of Montal and Muller(1,2) as well as Miller and Rudin.(3) The stability and geometric control enables the use of X-ray analysis of free-standing single bilayers. With the presented setup, simultaneous structural and electrophysiological measurements will become feasible.