**4. Summary and conclusions**

This paper provides a comprehensive, up-to-date review in a chronological order on the research progress made on condensation pressure drop in microscales. Also, studies on condensation pressure drop in microscales are summarized in a table. At the end, some suggestions for future work are presented. Therefore, the present study can not only be used as the starting point for the researcher interested in condensation pressure drop in microscales, but it also includes recommendations for future studies on condensation pressure drop in microscales.
