A summary of recent research in micropositioning and nanopositioning is presented. The work is classified into five groups by actuation approach, including piezoelectric, magnetic, electrostatic, thermal, and electrochemical microactuators. A consistent set of measurable, key characteristics are proposed: degrees of freedom, range, resolution, range-to-resolution ratio, footprint, force, natural frequency, and bandwidth. Values of the key characteristics are listed in tables. The results demonstrate the boundaries of current knowledge and the advantages of each actuation approach. This is the first time this information has been compiled in this growing field and it is summarized in such a way as to be useful to readers. There are 82 references cited in this review article.