If disposable flexible timers
could be cost reduced to ten cents or so each, they would be fitted to billions of bottles of hair dye, hair curler liquid and so on. This can only be done with printed electronics, preferably codepositing the beeper and interconnects at the same time. He timer would alarm at the appropriate preset time. Other applications could be a pot noodle or self heating food beeping at the correct time for consumption. In this case a printed sensor would detect when the boiling water is applied or the self heating is initiated.