Fabrication of high-accuracy microtranslation table for near-field optical data storage actuated by inverted scratch-drive actuators

We proposed a microtranslation table to convey a recording medium to a near-field optical head. The microtranslation table was fabricated on a silicon substrate with surface micromachining technology and consisted of inverted scratch-drive actuators (SDAs) actuated by electrostatic force. An object was translated by mounting it on the inverted SDA array. We observed that a micro object was translated in the direction of the fabricated SDAs by applying AC voltage of +/-600 V at 100 Hz. The dimension of the SDA plate was 70 mum long, 70 mum wide, and 1.3 mum thick and it has 1.5-mum-high bushing. We proposed a novel mechanism for releasing the SDAs from the object by retracting them. By applying the voltage of 65 V between the SDA plate and the lower electrode, the plate was retracted 160 nm down. Therefore, the X-Y translation is possible by placing the inverted SDAs in four different directions.