Growth Errors
In the kTAM, a growth error, an example of which can be seen in the figures below, occurs when one or more sides of a tile which binds to an assembly have glues which do not match the adjacent glues (called glue mismatches). Such a tile may bind with insufficient strength to remain permanently bound, but before it has an opportunity to dissociate, a previously unoccupied neighboring position may be filled by a tile which binds without mismatches, thus resulting in an assembly where every tile has sufficient strength to remain permanently attached despite the mismatch. This essentially "locks" the incorrect tile into place and potentially allows assembly to proceed with an incorrectly placed tile which may cause further deviations from the desired shape or pattern.