Functionalized pyroelectric sensors for gas detection

A new calorimetric gas sensor based on functionalized integrated pyroelectric detector arrays was fabricated and tested. The advantages of this sensor are mainly based on its miniaturized design enabling a close-by arrangement of sensing and reference structures. The low heat capacity and high thermal isolation of the sensor elements enable in principle the application of integrated low power heating structures. Lead–zirconate–titanate (PZT)-based detector arrays were fabricated on silicon and mounted in test packages adapted to the printed circuit board (PCB) containing a simple readout circuitry. The performance of two different types of sensor surface functionalisations was studied. A polymer coating with polydimethylsiloxane (PDMS) was chosen to detect heptane absorption. A detection limit of 10 ppm heptane was found. Bacterial surface layers functionalized with small Pt clusters were applied to study catalytic oxidation of hydrogen. Within the investigated range from 0.5 up to 3.5 vol.% hydrogen, no saturation of the detection signal was observed.