Embedded textile heat flow sensor characterization and application

• A textile heat flow meter sensor flexible and permeable to water vapor was developed.
• A proper calibration corresponding to the intended purpose of use is required for the textile flow meter sensor.
• The flow meter sensitivity depends on temperature. For applications with a large variation in temperature, the compensation is required.
• The textile flow meter sensitivity has a significant and complex variation with the variation in moisture content.
• The textile flow meter sensor can measure the heat flow and the heat losses by evaporation.

Measuring heat flow can be useful in determining the amount of heat exchanged between the human body and the environment in order to improve the comfort, efficiency and sometimes, the safety of the wearer. Scientists use passive heat flow sensors to measure body heat exchanges with the environment. In recent years, several such sensors have been developed and concerns about their proper calibration have been expressed. Moreover, the existing heat flow sensors are impermeable and prevent evaporation which gives inaccurate results when the evaporation phenomenon is present. We developed a flexible heat flow sensor which is permeable to water vapor. This sensor takes into account the evaporation phenomenon and allows a better measurement of the energy during the heat exchange. This paper describes the textile heat flow sensor realization, calibration and possible applications.