Abstract: The present invention provides a micro-electro-mechanical-system (MEMS) temperature sensor that employs a suspended spiral comprising a material with a positive coefficient of thermal expansion. The thermal expansion of the suspended spiral is guided to by a set of guideposts to provide a linear movement of the free end of the suspended spiral, which is converted to an electrical signal by a set of conductive rotor azimuthal fins that are interdigitated with a set of conductive stator azimuthal fins by measuring the amount of capacitive coupling therebetween. Real time temperature may thus be measured through the in-situ measurement of the capacitive coupling. Optionally, the MEMS temperature sensor may have a ratchet and a pawl to enable ex-situ measurement.

Abstract: A switch, such as an electromechanical or optical switch, whose state is responsive to temperature history, for example temperature excursions above or below a critical temperature. An element of the sensor made from shape memory alloy changes shape when exposed, even temporarily, to temperatures above the Austenitic start temperature As or below the Martensite start temperature Ms of the shape memory alloy sensor element. The shape change of the SMA element causes the sensor to change between two readily distinguishable states. The sensor can include a one-way stop element that creates a persistent indication of the temperature history. The switch also has built-in stops allowing the sensor to be manufactured and stored at temperatures above the Austenitic temperature without causing the indication of an over-temperature event, before the actual use.

Abstract: A time-temperature indicator indicates the useful shelf life of an associated product which may be affected by the passage of time and an applied temperature. A creeping material has a first end connected to a first fixed location and a second end connected to a load applying device such as a spring. In response to application of the load applying device, the passage of time, and the application of various temperatures, the creeping material will increase in length in a known manner. An indicator associated with the creeping material indicates whether the passage of time and application of various temperatures have caused the associated product to exceed its useful shelf life.

Abstract: The temperature of a heated roller (1) is monitored by a heat sensor (19) which rests on metal rectangle (25) on polyimide strip (5). The top end of the strip is attached directly to the frame (3). the bottom end of the strip has a hole (7), which receives an arm (9a) of pivoted member (9). A coil spring (13) pivots member 9 to cause arm 9a to pull the strip into contact with the heated roller. Because of the wide contact and low force between the strip and the roller, wear is reduced and smooth operation is realized.