Formation even of single suspended lipid membranes (black lipid membranes or) is notoriously difficult and unreliable and the resulting membranes often lack stability (1). After having almost fallen into disuse in the physiological community since the advent of the patch clamp technique, in recent years, suspended synthetic membranes have become increasingly important as systems for the reconstitution of organellar and bacterial ion channels and transport pores and as substrates for analytical single-molecule techniques based on biological nanopore recording (2). However, the capricious nature of the technique still reserves it to highly specialized laboratories.

We here show a novel method that allows the automated and highly reliable (100% yield) and instantaneous formation of lipid bilayers on a recently developed 4x4 microelectrode cavity array (MECA), yielding 16 highly stable suspended membranes into which ion channles and nanopores can be reconstituted. The method is an automated version of the classical Müller-Rudin painting method, where phospholipid in organic solvent is spread across an array of microcavities (dimatere: 5-50 µm) in a hydrophobic polymer substate using a remotely an magnetically actuated element. Due to the hydrophobic surface of the polymer, this results in instantaneous bilayer formation. Bilayers can be destroyed, e.g. by electroporation, and repainted multiple times with 100% success rate. Because each cavity contains an individually contacted Ag/AgCl-microelectrode, ionic currents through reconstituted ion channels and nanopores can be recorded against a common reference electrode in the bath. The small surface area and low capacitance of the membranes and the excellent dielectric properties of the polymer (SU-8) allows recordings to be made with low noise and high bandwidth (e.g. < 500 fA rms @ 10 kHz).

(1) "Planar bilayers can be extremely frustrating. All of us who have worked with them have, at one time or another,been reduced to irrational (but satisfying) acts of anger. [...] The number of beakers I sent crashing against the laboratory wall decreased as my understanding of the physical chemistry of the system increased." S.H. White In: Miller, C. (Hrsg.) Ion Channel Reconstitution, p. 3-35, Plenum, New York, 1986 (2) Demarche et al. Analyst 6, 1077, 2011

Figure 1