US Patent 11166343 Multi polymer positive temperature coefficient heater

A heating element includes a first bus bar disposed to receive current from a power source, and a second bus bar non-adjacent to the first bus bar. The heating element further includes a polymer ink section extending between the first and second bus bars, and the section includes a plurality of PTC polymer inks each different from one another. The second bus bar is electrically connected to the first bus bar via the polymer ink section.