Foldamers are classified into three different categories: peptidomimetic foldamers, nucleotidomimetic foldamers, and abiotic foldamers.  Peptidomimetic foldamers are synthetic molecules that mimic the structure of proteins, while nucleotidomimetic foldamers are based on the interactions in nucleic acids.  Abiotic foldamers are stabilized by aromatic and charge-transfer interactions which are not generally found in nature.  The three designs described below deviate from Moore's strict definition of a foldamer, which excludes helical foldamers.