The invention includes apparatus and methods for electrotransport of a drug or other beneficial agent through a skin or mucosal membrane surface. Specifically, the method employs X-ray diffractometry to examine qualities based on, for example, BA wherein A and B are peak intensities relevant to LnxOy and LnF3, respectively. This method provides an optimal operating condition to a fuel cell, thereby ensuring a high power. In the preferred embodiment, the pattern reader is an electro-optical sensor, and the encoded pattern includes a grid of dots arranged in a first predetermined number of dot code cycles wherein each dot code cycle includes a second predetermined number of dots. The second drive outlet, mounted on the arm of the first set of planet gears, drives at a different speed, and is coupled with a second sun gear meshed in the ring gear and drives a second set of planet gears.