David Gracias, assistant professor of chemical and biomolecular engineering and affiliated faculty member of Johns Hopkins Institute for NanoBioTechnology, lead a team of researchers that developed tiny microgrippers that can be controlled by harmless chemicals and magnets. This tiny tool, which closes around an object like a hand, could be used to conduct minimally invasive biopsies. Experiments using the device were reported in Proceedings of the National Academy of Sciences (Early Edition for the week of Jan. 12-16). Several news outlets, including the July 13, 2009 issue of The New York Times and ScienceDaily.com featured stories on the mircrogrippers, as well as videos that demonstrated how it works.
Here is a link to the story as it appeared on Headlines@Hopkins: http://www.jhu.edu/news_info/news/home09/jan09/gracias.html.