Humans have intrinsic limitations in manual positioning accuracy due to small involuntary movements that are inherent in normal hand motion. Among the several types of erroneous hand movements, physiological tremor is well studied and documented. Physiological tremor is roughly sinusoidal, in the frequency band of 8 – 12 Hz, and measures about 50 μm rms or more in each principal direction. Physiological hand tremor degrades the quality of many micromanipulation tasks and is intolerable in certain critical applications such as microsurgery and cell manipulation. In the human hand, humans are already in possession of a high dexterity manipulator with an unbeatable user interface. Hence, instead of replacing the human hand with a robotic manipulator, Riviere et al. [Riviere et al., 2003] proposed a completely handheld ophthalmic microsurgical instrument, named Micron, that senses its own movement, distinguishes between desired and undesired motion, and deflects its tip to perform active compensation of the undesired component (Fig. 1).