Flexure-based Manipulator for Active Handheld Microsurgical Instrument.

This paper presents the design and initial experimental results of a flexure-based parallel manipulator that is actuated by three piezoelectric stacks. The manipulator is for an active handheld tremor canceling device for microsurgery. By using flexures to approximate pin and ball joints, errors due to friction, backlash, and imperfect assemblies have been eliminated. The results show that the manipulator is capable of tracking motions similar to physiological tremor in amplitude and frequency. The workspace of the manipulator is more than 7 times larger than the tremor space in the x and y axes, and about 1.5 times larger in the z axis. One dimensional and three dimensional tracking tests had rms errors of 6.5 μm and 12.1 μm respectively.