the memory cell or the memory array formed of such memory cells has different molecular or polymeric layers forming an electrochemical redox pair . a matrix acting as proton donors or acceptors is provided in the two different molecular or polymeric layers . if a corresponding voltage is applied between mutually crossing upper and lower interconnects , one layer of their molecules emits electrons to the interconnect . as a result the molecules are oxidized . at the same time , electrons flow from the other interconnect into the molecules of the other polymer layer . as a result the molecules of that layer are reduced . charge transport is balanced by proton flow , so that the oxidation state of the two layers is stabilized . if the voltage polarity is reversed , the memory cell is rewritten to the initial form . the memory array is suitable where the number of read - outs significantly exceeds the number of write operations , for example in smart cards .