Systems and methods for detecting andor identifying target cells using engineered transduction particles are described herein. The article is comprised of a metal or metal alloy substrate having on its surface a coating which is an oxide of the metal or metal alloy. The position of the drivable element can be detected by a simple construction and the drivable element can be quickly returned to an original position. The listing may be ordered according to the rating information in order to facilitate the selection of programs for a parameter set.