The Gracias‘ microgripper video is now on Metacafe for those that have never seen it. The video shows a microgripper sliding down a test tube and grabbing a sample of cow tissue. The device is thermally triggered to close, and is magnetically driven. The video is shown below, there is no sound.
Link to paper for those interested: Tetherless thermobiochemically actuated microgrippers
A digested version of this research was written up by Lewis Brindley for the RSC Chemistry World: Micro-machines get a grip