A micro flow sensor from a polymer for gases and liquids

In this paper, we present a micro flow sensor from a polymer based on the thermal anemometric principle. A sensor with outer dimensions of 5.5 x 6 x 1.2 mm(3) and a small fluidic channel with a cross-section of 240 mu m x 400 mu m may be operated with both gases (up to 200 ml min(-1)) and liquids (for water up to 200 mu l min(-1)). Due to its small heat capacity, the sensor is also suitable for dynamical measurements of liquid flows, e. g. flow pulsations up to several 100 Hz even within high-pressure hydraulic systems.