Cell-inspired electroactive polymer materials incorporating biomolecular materials

摘要

In this paper, we discuss a new form of electroactive material that consists of both synthetic polymers and biological molecules. This modular material system is inspired by the compartmentalized and hierarchical orga-nization of cellular systems and features an artificial cell membrane, or lipid bilayer, which acts as the primary transduction element in the material. Building on recent developments by our group, the lipid bilayer is formed at the interface between phospholipid-encased hydrogel volumes surrounded by oil and contained in a solid sub-strate. Results are presented that demonstrate how the electromechanical properties of the lipid bilayer can be used for both static and dynamic sensing and actuation. Specifically, a relative change in length of the outer substrate of 10 —15% due to an applied force yields large changes in capacitance (> 90% reduction) or resistance (20 — 30% increase) depending on the composition of the bilayer. The capacitive nature of the membrane is also used in a dynamic sensing application, whereby the perturbation of an artificial hair structure induces bending in a bilayer formed at the base of the hair. This oscillation results in a time-varying membrane capacitance that in turn produces an electrical current on the order of 1 — 100pA. The ability to actuate the amount of contact between neighboring modules is also discussed and a concept for fabricating higher-order biomolecular arrays that connect internally to form networks of lipid bilayers is also presented.