Failure Pressure of Bilayer Lipid Membranes

The motion and growth of plants is the inspiration for a new biomimetic actuator that uses fluid transport across a bilayer lipid membrane (BLM) to create internal pressure and cause displacement in the actuator. In order for the actuator to be viable the BLM must be able to withstand this internal pressure without failing. In this study BLMs are formed over a porous polycarbonate substrate and a hydrostatic pressure is applied to the BLM and gradually increased until it fails. This test is performed over different pore sizes to measure the failure pressure of the BLM as a function of pore radius. A similar test is used for polymer films to compare the failure pressure trends of a BLM to conventional engineering materials. The polymer films and BLMs are modeled as a simply supported circular plate under uniform load, first with the assumption of small deflections and then with the assumption of large deflections. It was found that the large deflection model better represents the trend of failure pressure versus pore radius than the small deflection model.