Polymer PTC Materials Integrating Self‐Adaptive Thermal Control and Temperature Measurement

ABSTRACT Conventional temperature‐control systems generally rely on separate heaters, temperature sensors, and controllers, resulting in complex wiring and structural redundancy. This study proposes a proof‐of‐concept strategy in which a single polymer positive temperature coefficient (PTC) composite simultaneously performs self‐regulating heating and resistance‐based temperature measurement. The composite consists of an olefin block copolymer/stearic acid matrix filled with carbon black and expanded graphite, forming a three‐dimensional point–plane hybrid conductive morphology. The material exhibits a PTC transition temperature of approximately 60°C, a maximum temperature coefficient of resistance of 103% °C −1 , and an overall PTC intensity of 6.2. Under an applied voltage of 10 V, increasing the ambient temperature from 15°C to 30°C resulted in a peak‐to‐peak steady‐state temperature variation of only 2.2°C. At an ambient temperature of 25°C, the composite reached steady‐state temperatures of approximately 62°C–64°C over an operating voltage range of 6–12 V, with a peak‐to‐peak variation of 2.3°C. An error‐propagation model was further established to quantify the temperature‐estimation performance and identify the temperature coefficient of resistance as the dominant factor governing temperature resolution. Within the tested strong‐PTC window of 60°C–65°C, the temperature inferred from the calibrated resistance–temperature relationship showed a maximum deviation of approximately ±0.1°C relative to the PT100 reference under the investigated conditions. These results demonstrate the feasibility of integrating self‐regulating heating and temperature sensing into a single lightweight PTC composite and provide a methodological basis for highly integrated thermal‐management devices.