TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Components: The first and/or second substrate includes substance containing chamber (100). The substance containing chamber comprises substance containing gas that may be evolved by heating. The resistive heater portion(s) borne by the second substrate layer is suspended across the chamber or aperture (110) extending through the second substrate layer. The second substrate layer and/or top layer include gas collecting chamber (120). The first bonding layer (25) comprises thermosetting resin, phenolic resin, or epoxy material. The second substrate layer comprises medial layer with two sides. The resistive heater is on the first side of the medial layer. The conductive traces are on the second side of the medial layer. The conductive traces are electrically coupled to the resistive heater by conductive material disposed in the opening extending through the medial layer. The resistive heater borne by the second substrate layer also comprises catalytic layer for catalyzing gas generation reaction and thermally removable coating covering the catalytic layer. The catalytic layer comprises ruthenium, platinum, or nickel. The thermally removable coating comprises paraffin or polymer. The resistive heater borne by the second substrate also comprises thin film patterned in serpentine pattern, transition metal patterned and used to provide resistive heating, ruthenium plating on the transition metal to provide catalytic layer, and polymer coated on the catalytic layer to provide thermally removable coating. The resistive heater borne by the second substrate is tantalum-aluminum alloy, nickel-chromium, molybdenum, tungsten, nickel, palladium, platinum, silver, gold, silicon, and/or their alloys. The first and second substrates comprise polyester, polyether ether ketone, polyimide, or polyether imide. The hydrophobic layer comprises (expanded) polytetrafluoroethylene (PTFE), fibrillated PTFE, or micro porous PTFE. The top layer comprises sub-layers. Preferred Methods: The method also comprises feeding the first substrate layer, second substrate layer, hydrophobic layer, first and second bonding layers, and/or top layer from feed reel, and taking up the completed resistive heater assembly on a take-up feed reel. The second substrate layer is bonded to the first substrate layer by laminating the first bonding layer between the second substrate layer and first substrate layer. The hydrophobic layer is bonded to the top layer by laminating the second bonding layer between top and hydrophobic layers.