Characterization of Porous Substrates for Biochemical Energy Conversion Devices

摘要

Bimolecules have demonstrated the potential to function as active components in energy harvesting devices, biosensors and bioinspired actuators. The bilayer lipid membrane (BLM) formed from lipid molecules and supported in the pores of porous substrates is the standard platform for fabricating the biomolecule based devices. The techniques for forming BLM in an in-vitro environment like lipid painting, Lagmuir-Blodgett, Langmuir-Schaffer and lipid folding methods were developed by researchers in the biophysical community to investigate the properties of membrane bound proteins. While all of these methods can form a BLM and has been used in laboratory research for few decades, they are not equally well-suited for fabricating an engineering device. Of the different methods, the lipid deposition technique for BLM self-assembly and protein insertion is the closest in its qualities to an engineering prototyping method. This article presents a detailed electrical model of the substrates and the BLM formed in the pores from SOPC, POPS:POPE and DPhPC lipids using lipid deposition technique. The equivalent circuits of the substrates and the BLM are used to interrogate the quality of the BLM by impedance spectroscopy. The deviations of the prepared BLMs from desirable parameters are traced to the preparation procedure that could be used as a feedback information for fabricating a single BLM in the pores of the substrate. The impedance response is also used to understand the change in electrical properties of BLMs formed in an array of pores of a multi-porous substrate.