Metamaterials are artificial composite structures with unusual physical properties such as the perfect absorption of light, which can be exploited to improve the spectral sensitivity and selectivity of thermal detectors. The desired detector characteristics are engineered by tuning the absorption properties of metamaterials. The numerical simulations demonstrate polarization-independent absorption of disc-shaped dielectric/metallic absorbers and their integration capability in thermal detectors.

Hydrogen detection for purposes such as smart gas metering or fuel cell safety can be done by using a low-cost off-the-shelf thermopile IR radiation sensor and by driving it as a TCD (thermal conductivity detector). The MEMS thermopile sensor element is exposed to the measured gas environment. By applying an AC heating voltage to the thermopile structure and by measuring its DC output voltage, the hydrogen concentration of its gas environment can be measured with a resolution of up to 3.7ppm.