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Aerosol particulate matter (PM) is a known risk factor for lung and liver cancer. In particular, PM under 1 μm in diameter (PM1) is very dangerous for health, affecting the respiratory system with several heavy outcomes and reaching other human districts like liver, where foreign substances are processed. Today PM1 is still difficult to be detected on-field with standard techniques and this paper reports a comparison between two sensing approaches for environmental particulate monitoring, which are suitable for miniaturization and integration into portable and low-cost devices. Specifically, transducers based on surface acoustic waves (SAW) and electrochemical impedance spectroscopy (EIS) were comparatively investigated as alternatives to more common but also expensive optical methods. Moreover, their performances were evaluated for the detection of nanoparticles of different dimensions (1 μm, 200 nm and 40 nm) to mimic different compositions of PM1 and reach a size scale which is an order of magnitude below present literature. Notably, both transduction methods were able to detect the presence of PM1 particulate. The SAW-based approach showed better performances in terms of sensitivity and detection of nanoscale particles, although the EIS strategy has a competitive sensitivity considering also its even lower cost.

The dielectric properties of YCTO bulk capacitors were investigated as a function of temperature from 25 degrees C to 150 degrees C and at microwave frequencies in comparison to a SiO2 bulk sample. The results confirm the high-k character of the YCTO ceramic, in addition to the low AC conductivity, namely epsilon' = 40.1 and sigma = 6 x 10(-8) S cm(-1) at 1 MHz, and show a weak frequency and temperature (25 degrees C-150 degrees C) dependence. A temperature coefficient value of -601 ppm degrees C-1 for the dielectric constant (TC epsilon') was estimated at 100 kHz. In the GHz regime, a comparison with bulk SiO2 confirms the higher YCTO dielectric permittivity. These results demonstrate high-k YCTO ceramic as a very promising material with high potentiality for electronic applications.