An NROM flash memory cell is implemented in an ultra-thin silicon-on-insulator structure. Further, the present invention provides single-hole hollow polymer particles produced by the method for producing single-hole hollow polymer particles. Light electropolishing removes no more than about 5 percent by weight of the device ). The first divided body is provided with a flexible arm having a latch, and the restricting wall of the second divided body is provided with a notch, constituting first locking mechanism. A second voltage applied to the second set of stator comb tines operates to pull the rotor tines toward the second set of stator comb tines, enabling bi-directional operation. The body and the alignment arm each have a series of ball alignment lines to aid in placement of the ball relative to the feet placement cutouts.