Air bag inflator with mechanism for deactivation of second stage and autoignition

An inflator for an inflatable vehicle occupant protection device, said inflator comprising:

• a housing;
• an inflation fluid source in said housing for, when actuated, providing fluid for inflating the protection device;
• an electrically actuatable initiator connected with said housing for, when actuated, actuating said inflation fluid source;
• and
• an autoignition assembly actuatable in response to an increase in temperature in said housing above a predetermined temperature to cause actuation of said inflation fluid source, said autoignition assembly comprising an electrically energizable microelectromechanical system device (MEMS device).

An inflator for an inflatable vehicle occupant protection device, said inflator comprising:

• a primary inflation fluid source and a secondary inflation fluid source actuatable independently of each other;
• vehicle electric circuitry for (i) sensing an occupant protection event for which inflation of the protection device by only said primary inflation fluid source is desired and (ii) actuating said primary inflation fluid source to inflate the protection device without actuating said secondary inflation fluid source;
• and
• a microelectromechanical system device (MEMS device) electrically energizable to actuate said secondary inflation fluid source a predetermined period of time after actuation of said primary inflation fluid source in response to sensing of said occupant protection event.