Transmembrane proteins are functional macromolecules that direct the flow of small molecules and ions across a lipid bilayer. Here, we propose the development of helical peptide amphiphiles that will serve as both the bilayer and the functional unit of a self-assembled peptide bilayer membrane. The peptide, K3L12, was designed not only to possess dimensions similar to that of a lipid bilayer but also to yield a structurally robust, alpha-helical bilayer. The formation of alpha-helices is pH-dependent, and upon annealing the sample, a transition from alpha-helices to beta-sheets can be controlled, as indicated by optical and vibrational spectroscopies. Imaging the materials confirms morphologies similar to that of a lipid bilayer but rich in alpha-helices. Annealing the samples yields a shift in the morphology from bilayers to curled disks, fibers, and sheets. The structural robustness of the material can facilitate the incorporation of many functions into the bilayer assembly.