Microwave sensor concept for the detection of gas inclusions inside microfluidic channels

In this contribution a new sensor concept for the detection of gas inclusions in microfluidic channels is presented. The sensor operates at microwave frequencies with two microstrip patch antennas. To prevent gas embolism in a variety of clinical branches the sensor yields a powerful detection since patch antennas operate at different frequencies for different permittivities surrounding them. Simulations and measurements reveal that monitoring of the shifting resonance frequency indicates changing materials like gas in liquids.