A microhand is a miniature robotic end effector, which is a device or tool connected to the end of a robot arm. A microhand is designed to grasp, hold and manipulate objects in a manner similar to the functioning of a human hand but on a much smaller scale. A prototype microhand developed at the University of California, made of silicon wafers, measures approximately one millimeter (1 mm) across when its four "fingers" are closed. The moving parts are driven by pressurized gas, allowing use of the device under a variety of conditions. The device's small size and high precision have aroused interest among surgeons, who envision it as a potential tool for performing critical operations in the human body. A sophisticated microhand may incorporate an eye-in-hand system, to enhance maneuverability and precision. Components of such a system include a camera specialized for work at distances of a fraction of a millimeter and a lamp for use in dark environments, such as the inside of blood vessels or organs. An optical fiber system transmits light for the lamp and images captured by the camera