The design of polymers that mimic the complex structures and functions of bio-molecules is of paramount importance with both fundamental and practical implications. However, this effort is often limited by our knowledge of the microscopic-level driving forces behind certain structures and properties. Computations allow for direct probing of this information. Moreover, given a primary sequence for a polymer, they can be utilized to predict its conformational properties. This presentation will report some recent progress in using computations to guide the design of biomimetic antimicrobial material. Specifically, the conformational properties of proposed polymer backbones were examined with different levels of computational approaches before they were synthesized. First, density functional theory calculations are employed to search for stable conformations of selected polymer fragments and to determine the torsional potentials around various bonds on the polymer backbone. The torsional potentials are then applied to predict the conformational properties of the polymers using classical simulations. These calculations also yield useful insights on how various structural motifs (e.g., conjugation, hydrogen bonding, and side chain substitution) enforce desired conformation. Available experimental results show that the resulting polymers have promising antibacterial activities