Direct fabrication of SU‐8 microchannel across an embedded chip for potentiometric bilayer lipid membrane sensor

Abstract

AbstractMembrane proteins play a critically important role, especially in molecular and cellular transport processes, which makes them the most prevalent drug targets and also to be a good sensing element for biosensing applications. However, the skill‐dependent and manual fashion to form bilayer lipid membranes (BLMs) has limited their use for application purposes. Here, we introduce a fabrication technique of SU‐8 microchannel suitable for microfluidic‐based BLM formation and show a preliminary step of our ISFET‐based BLM sensor. Making notches on the corners of a rectangular through‐wafer hole etched in a silicon carrier substrate reduced the gap width between an embedded chip and the carrier as close as possible, leading to the gap depth of 4 μm. SU‐8 microchannel on the chip‐carrier assembly was directly fabricated by UV exposure through a bonded quartz lid and developing SU‐8 through the fluidic ports drilled in the lid, without needing a sealing process typically causes an alignment mismatch or void formation. Finally, the capability to form BLMs was tested and proven by the successfully encapsulated fluorescent dye in microwells fabricated on the embedded chip. This paper is the first report of the successful formation of BLMs on a chip‐in‐carrier assembly by the microfluidic method.