A fluorescent micrograph of viable cells captured using a biochemical trigger to actuate the gripper. Courtesy of the National Academy of Sciences (PNAS).

A remote-controlled microgripping "hand" could help give surgeons greater control during minimally invasive surgeries such as biopsies. In a story last August, frequent TR freelancer Prachi Patel-Predd described how the tiny hand works. Now the Johns Hopkins University researchers developing the microgripper have published a paper in the Proceedings of the National Academy of Sciences updating their work and including some neat video footage (see below). In the clip, the researchers use magnets to navigate a gripper through a coiled tube and to guide it toward a dyed bead and a cell mass. The grippers can close like a fist around an object in response to biochemical cues; in the future, they could even respond to biomolecules characteristic of cancer cells. The microhand in these videos grips the blue bead and the cell mass in response to an increase in temperature.