Free-standing biomimetic polymer membrane imaged with atomic force microscopy

Fluid polymeric biomimetic membranes are probed with atomic force microscopy (AFM) using probes with both normal tetrahedrally shaped tips and nanoneedle-shaped Ag(2)Ga rods. When using nanoneedle probes, the collected force volume data show three distinct membrane regions which match the expected membrane structure when spanning an aperture in a hydrophobic scaffold. The method used provides a general method for mapping attractive fluid surfaces. In particular, the nanoneedle probing allows for characterization of free-standing biomimetic membranes with thickness on the nanometer scale suspended over 300-μm-wide apertures, where the membranes are stable toward hundreds of nanoindentations without breakage.