Abstract: A micro driver includes a translational unit, an actuating unit and a rotational unit. The translational unit includes translational elements movable relative to one another. The actuating unit includes two opposite actuators connected to each of the translational elements. The actuators are operable to move the translational elements relative to one another. The rotational unit includes a frame and semi-spheres each located in an aperture defined in the frame and in contact with the uppermost one of the translational elements so that the uppermost translational element rotates the semi-spheres on the frame when the actuators causes the translational elements to move relative to one another.

Abstract: A quantum-dot resonant-tunneling device apparatus is provided. The quantum-dot resonant-tunneling device apparatus includes a pair of top-and-down N-type electron injection layers and a pair of quantum-dot layers sandwiched with at least a period of double-barrier. The pair of top-and-down N-type electron injection layers is provided with an adequate positive or negative electric field which leads to electronic resonant-tunneling transportation in the quantum-dot layers mentioned above. In addition, once the electrons are tunneling transported in the device, the device serves as a negative resistance device. The device does not only provide bipolar negative resistance capability and a superior temperature stability within a very wide temperature range, but also operates well under room temperature.