PPTC heater and material having stable power and self-limiting behavior

1. A resistance heater, comprising:

a polymer positive temperature coefficient (PPTC) material, arranged in a ring shape that defines a heater body; and

an electrode assembly, comprising two or more electrodes arranged in contact with the heater body at two or more locations,

wherein PPTC material comprises:

a polymer matrix, the polymer matrix defining a PPTC body; and

a conductive filler component, disposed in the polymer matrix, wherein the two or more electrodes comprise a bottom electrode on a first side of the heater body, and a top electrode, disposed on a second side of the heater body, opposite the first side, the top electrode and the bottom electrode being arranged generally in a ring shape, and

wherein the top electrode and the bottom electrode each includes two segments, wherein a first pair of segments in the top electrode are separated from one another by a first gap and a second gap, wherein a second pair of segments in the bottom electrode are separated from one another by a third gap and a fourth gap.

2. The resistance heater of claim 1 , the ring shape of the PPTC material comprising a circular ring, a rectangular ring, an elliptical ring, an oval ring, or a polygonal ring.

3. The resistance heater of claim 1 , the conductive filler component comprising a carbon filler and/or conductive ceramic component, disposed as a plurality of particles within the polymer matrix.

4. The resistance heater of claim 1 , wherein a volume percentage of polymer matrix is between 50˜99%.

5. The resistance heater of claim 1 , the conductive filler comprising a graphene filler component, and/or a carbon nanotube filler component.

6. The resistance heater of claim 1 , further comprising a first lead and a second lead, electrically connected to the electrode assembly, the first lead and the second lead extending perpendicularly to a main plane of the heater body.

7. The resistance heater of claim 1 wherein the heater body is disposed on a printed circuit board (PCB) substrate, the PCB substrate being arranged in a ring shape.

8. The resistance heater of claim 7 , the heater body and the electrode assembly together comprising a thickness of approximately 2 mm, and the PCB substrate comprising a thickness less than 1 mm.

9. The resistance heater of claim 7 , the PCB substrate comprising FR4, copper inlay PCB, or a ceramic PCB, the ceramic PCB comprising Al 2 O 3 or AlN.

10. A camera, comprising:

a transparent lens portion; and

a resistance heater, disposed on a periphery of the transparent lens portion, and comprising:

a polymer positive temperature coefficient (PPTC) material, arranged in a ring shape within a plane, and defining a heater body, wherein the PPTC material comprises:

a polymer matrix, the polymer matrix defining a PPTC body, and

a conductive filler component, disposed in the polymer matrix; and

an electrode assembly, comprising a bottom electrode on a first side of the heater body, and a top electrode, disposed on a second side of the heater body, opposite the first side the top electrode and the bottom electrode being arranged generally in a ring shape,

wherein the top electrode and the bottom electrode each includes two segments, wherein a first pair of segments in the top electrode are separated from one another by a first gap and a second gap, wherein a second pair of segments in the bottom electrode are separated from one another by a third gap and a fourth gap.

11. The camera of claim 10 , the ring shape of the PPTC material comprising a circular ring, a rectangular ring, an elliptical ring, an oval ring, or a polygonal ring.

12. The camera of claim 10 , the filler component comprising a carbon filler component, disposed as a plurality of carbon particles within the polymer matrix.

13. The camera of claim 10 , further comprising

a first lead and a second lead, electrically connected to the electrode assembly, the first lead and second lead extending perpendicularly to the plane of the heater body.

14. The camera of claim 10 , the conductive filler comprising a graphene filler component and/or a carbon nanotube filler component.