Capacitive Low Temperature Co-Fired Ceramic Fluidic Sensor

This paper proposes a fully embedded LTCC (Low Temperature Co-fired Technology) fluidic sensor based on capacitive effect. The proposed capacitive fluidic sensor is built up by ten layers carrying holes and a micro-channel. The micro-channel is placed between capacitor electrodes which are screen printed and embedded inside the substrate. The operating principle of this sensor is based on the measurement of capacitance variations evoked with different permittivity values of induced fluids. By inserting various fluids in the micro-channel, capacitance of the sensor changes according to different permittivity values. Detection of various fluids has been performed. Sensor was modeled and its performances were estimated through analytical calculations prior to its fabrication. Experimentally attained results are compared with electrical characteristics determined by and good agreement is achieved. Beside that sensor dependences on frequency were determined by direct measurements of capacitance in the frequency range of interest, where linearity of the capacitance was observed.