<title>Lipid bilayers suspended on microfabricated supports</title>

Abstract

The plasma membrane, that exists as part of many animal and plant cells, is a regulator for the transport of ions and small molecules across cell boundaries. Two main components involved are the phospholipid bilayer and the transport proteins. This paper details the construction of a micromachined support for bilayers (MSB) as a first step towards the development of highly selective and highly sensitive ion-channel based biosensors. The device consists of a~100 µm hole in a polymeric support above a cavity that can hold~25 nL of electrolyte. Electrodes attached to the structure allow the resistance of the membranes to be measured using d.c. conductivity. The MSB is made in two halves, using SU8 ultra-thick resist, which are subsequently bonded together to make the final structure. A layer of gold, surrounding the aperture, enables self-assembled monolayers of alkanethiols to be used to make the polymeric structure biocompatible. Lipid membranes have been formed over these holes with resistances comparable with those of natural membranes >10 7 Ωcm 2 . The ion-channel gramicidin has successfully been incorporated into the bilayer and its activity monitored. It is proposed that this type of device could be used not only for studying membrane transport phenomena but also as part of an ion-channel based biosensor.

Scalable micro-cavity bilayer lipid membrane arrays for parallel ion channel recording

“…However, small cavities have small in situ electrodes, which limits the chip lifetime or measurement duration [11,14]. Baaken et al developed a 4 × 4 array of micro-cavities using a single layer of SU8 [11], and Ogier et al fabricated micron sized cavities using a combination of SU8 and polymer films [12]. Suzuki et al fabricated a 96 well planar bilayer structure using stereolithography, with apertures patterned in parylene [13].…”

“…In order to increase throughput, bilayer arrays have been developed, for example using stereo-lithography to define chambers around a thin film of a hydrophobic polymer that includes an aperture for bilayer formation [9,10]. Both ease of bilayer formation and stability has been improved through the use of small cavities in the range 6-50 m diameter [11][12][13]. However, small cavities have small in situ electrodes, which limits the chip lifetime or measurement duration [11,14].…”