To confer a greater chemical diversity and to access unexplored conformational space, non-canonical amino acids have been introduced to form novel sequence-specific heteropolymers. Among them, peptoids or oligo-N-substituted glycines emerged as a major class of biomimetic materials and have been actively investigated. Like biopolymers, peptoids are information-rich and programmable at the monomer level, offering precise control of chain length, structure, and functionality. The structural similarity to polypeptides confers the impressive diversity of conformation and biological activity observed for peptoids; moreover, non-natural backbone renders them greater stability in physiological conditions (i.e., protease-stable). Using the unique properties, the peptoid are actively investigated to mimic natural peptides. Our ongoing efforts to develop novel antimicrobial peptoids and cyclosporine mimics will be presented.