Thermal sensing polymeric capacitor
AssigneeMotorola, Inc.
InventorsFlorence O. Eschbach, Jose M. Fernandez
Life of this patent
Estimating the term…
Abstract
A thermal sensing polymeric device (110) such as a capacitor is fabricated from a layer of a copolymeric material (112) including polyvinylidene fluoride and a fluorinated ethylene. The fluorinated ethylene may be selected from the group including trifluoroethylene and tetrafluoroethylene. The thermal sensing polymeric device may be a capacitor fabricated of polyvinylidene fluoride-trifluoroethylene copolymeric material. In such an application, the capacitor device exhibits a change in capacitance as the temperature to which the device is exposed is changed. Specifically, as the temperature of the polymeric material crosses a threshold transition temperature, a substantial change in its capacitance is observed.
Claims22
A thermal sensing polymeric device comprising a polymer characterized by a ferroelectric to paraelectric transition temperature which occurs below the melting point of said polymer, said polymer effecting a change in dielectric constant at temperatures in excess of said transition temperature.
A rechargeable battery pack comprising:
- at least one battery cell;
- at least a pair of charging contacts for connecting said battery pack to a source of charging current;
- and
- a polymeric capacitor device disposed between said battery pack and said source of charging current, said polymeric capacitor comprising a polymer characterized by a ferroelectric to paraelectric transition temperature, said polymer having a first capacitance at temperatures below said transition temperature, and a second capacitance at temperatures above said transition temperature.
Dependencies are inferred from the claim text.