  Genetic circuit design is a well-studied problem in synthetic biology. Ever
since the first genetic circuits -- the repressilator and the toggle switch --
were designed and implemented, many advances have been made in this area of
research. The current review systematically organizes a number of key works in
this domain by employing the versatile framework of generalized morphological
analysis. Literature in the area has been mapped based on (a) the design
methodologies used, ranging from brute-force searches to control-theoretic
approaches, (b) the modelling techniques employed, (c) various circuit
functionalities implemented, (d) key design characteristics, and (e) the
strategies used for the robust design of genetic circuits. We conclude our
review with an outlook on multiple exciting areas for future research, based on
the systematic assessment of key research gaps that have been readily
unravelled by our analysis framework.
