What kind of research do mechanical engineers do?

<p>See title. What kind of research can mechanical engineers do, and what is the kind of day-to-day life of a researching ME?</p>

<p>Also, is a phd usually a requirement to work in a research job in mechanical engineering, or is a thesis-plan MS sufficient? I'm just getting into looking into graduate school and research prospects for mechanical engineering, so I'm sure I'm coming off as a newbie here.</p>

<p>Thanks :)</p>