A handheld marking instrument includes a body having a substantially flat shape, a first chamber formed within the body and having an inner surface configured to receive and contain a marking substance within the body, and a first marking device configured to deliver the marking substance to a desired surface during marking. In one embodiment, a sensor air passage utilizes a low pressure region created by the blower to draw air through the passage. The planarized layer partially removed, and an upper portion of the gate electrode is exposed. The process optionally may comprise the addition of a powdered compound selected from the group of inorganic oxides, metals, and carbon-based compounds. , mobile devices, are described.