A monomer structure based on a hairpin loop is described that can be linked via short oligonucleotide sequences (linkers) to form polymers. Independence of linked monomers allow for exponential complexity of the polymer structure. A method is described wherein the polymer structure can be replicated semi-conservatively with fidelity, given a source of monomer structures and linkers. Furthermore, the separation of the product from the parent allows for exponential amplification. These steps are achieved by secondary structure constraints and toehold-mediated strand displacement, and occur in the absence of enzymes. The parallel polymerization allows for replication to be achieved in O(log N) time, as opposed to O(N) from a processive process.