An apparatus with a second movable portion that moves along an x-axis direction and a z-axis direction and a first movable portion that only moves along the z-axis direction is disclosed. An integrated circuit design method applied to these library cells includes the steps of rotating the second library cell to cause the metal track direction of the odd metal layers of the second library cell to be parallel to that of the odd metal layers of the first library cell, and placing the first library cell and the second library cell in an identical integrated circuit design. The second page may have a first and a second side with a moveable member mounted in between the first and the second pages. If the intake air flow direction reverses, the temperature distribution in the heater also reverses.