I'm looking for a thermocouple or some sort of flat/thin temperature-sensing device. The important temperature range will be 60-150 deg F (15-65 deg C). Ideally, it would be the thickness of single-ply cardboard or less (not corrugated cardboard), perhaps 1/4 inch wide and 2-4 inches long.
Can I buy wire that is sensitive to temperature, or is there some off-the-shelf solution that would work well for this?