temperature sensor on the diaphragm can ensure proper evaporative mixing and or reacting chamber 10 control is achieved on the evaporative pad 5 temperature sensors fabricated out of platinum can be used because platinum is a good for use in high temperature applications alternatively other high temperature performance materials may also be used the micro initiator 15 may also be fabricated as an array of thermally insulated freestanding wires typically mpgs do not mix chemical and air oxidizer efficiently however in the present invention there is sufficient time for the liquid chemical to evaporate into the low pressure evaporative mixing and or reacting chamber 10 while simultaneously an evaporated oxidizer supplied by the micro evaporators 5 or air supplied by the front inlet 35 rushes into the same evaporative mixing and or reacting chamber 10 the evaporative mixing and or reacting micro device of the present invention can contain integrated arrays of temperature and pressure sensors coupled with feedback loops which may control the ignition sequence of the micro initiators 15 for ensuring high operational reliability and efficiency although the present invention has been described in terms of the preferred embodiment above numerous modifications and or additions to the above described preferred embodiments would be readily apparent to one skilled in the art by way of example but not limitation this invention is best used for very light and compact chemical mixers reactors for example this invention enables the manufacture of very small chemical based heat engines in one embodiment the device 1 can have dimensions of approximately 8 u00d7 4 5 u00d7 38 mm the device of this embodiment contains no moving parts such as pumps or valves a non pressurized liquid fuel is used therefore the device of this embodiment contains no pressurized lines valves or pressurized tanks.