Researchers at the University of Toronto created a pair of tweezers capable of picking up, without causing damage, individual cells, using a force of as little as 20 nanoNewtons.
At their most sensitive, they exert only enough force to support 2 millionths of a gram against the pull of gravity.
The tweezers’ arms are about 3 millimetres long, with fine tips able to grasp cells just 10 micrometres across. In trials using pig heart cells, the pincer could pick up and move the cells without damaging them. Holding them with only 100 nanoNewtons of force, the gripper squashed the cells out of shape by only 15%.
The grippers are controlled by software that can identify individual cells and move the tweezers into position in just a few seconds.