During your master you need to do an internship and write a master thesis. This is possible both in the Netherlands and abroad. In order to give an insight into your quest to find a suitable internship or master thesis, Isaac Newton organizes a lunch lecture together with the faculty for both these issues.
The Mechanical Engineering program has a site where you can find everything there is to know about internships. Also, you are able to find an archive with all the internships of the past 5 years. This gives you a nice overview of the possibilities when choosing an internship. Furthermore, vacancies of internships are presented on this site. Remember to start in time when searching for an internship, especially if you want to do this outside of Europe. To help orientate you further on which internship to choose, a booklet is provided here with experiences from students that have done internships in- and outside Europe.
A master thesis, and the required research which comes along with a thesis, can be done both at the university and externally.