Thermoelectric cool-film flow sensor

Hemodynamics, specifically, fluid shear stress, plays an important role in the formation of arterial plaque known as atherosclerosis. For this application, hot-wire anemometers, being a robust and highly sensitive method for measuring flow properties, have a limitation in their sensitivity due to the effects of locally increasing temperature on nearby cell damage. Conversely, the effects of locally decreasing the temperature are diminutive and provide the capability for a larger temperature difference between the sensor and the ambient environment, thus increasing measurement sensitivity. In this abstract we show the new capability of using thermoelectrically-cooled sensors to detect flow rate. A flexible micro resistance-temperature-detector (RTD) was bonded to the surface of a thermoelectric cooler molded into the bottom of a flow channel using PDMS. The power required to maintain a constant surface temperature was increased as the flow rate through the channel was increased.