Chemical sensor based on a novel capacitive microwave flexible transducer with polymer nanocomposite-carbon nanotube sensitive film

Microsystem Technologies - This study presents the results on the feasibility of a resonant planar chemical capacitive sensor in the microwave frequency range suitable for gas detection and...     

Solidly Mounted Resonators with Ultra-High Operating Frequencies Based on 3R-MoS2 Atomic Flakes

Conventional bulk and thin piezoelectric materials based film bulk acoustic resonators (FBARs) are facing an insurmountable challenge for millimetric frequency applications due to the poor piezoelectric properties of the materials when their thickness reaches the sub-micron regime. Novel FBARs for ultra-high working frequencies are in urgent demand to meet the requirements of the fast-growing 5/6G telecommunication techniques. Recent advances in 2D piezoelectric nanomaterials create an opportunity in this perspective. Here, the first FBAR chip based on 2D 3R-MoS₂ ultrathin piezoelectric flakes with a solidly mounted resonator (SMR) architecture is reported. The typical resonant frequency for an SMR device based on ≈200 nm 3R-MoS₂ flake reaches over 25 GHz with high reproducibility. Theoretical and finite element analysis suggest that the observed resonance is of longitudinal acoustic modes. This study demonstrates for the first time that the access to 2D piezoelectric nanomaterials makes high performance piezoelectric devices feasible for various promising applications including high-speed telecommunication, acousto-optic, and sensor fields,etc.     

Wireless sensing and identification based on radar cross section variability measurement of passive electromagnetic sensors

In this paper, we present the wireless measurement of various physical quantities from the analysis of the radar cross section variability of passive electromagnetic sensors. The technique uses a millimeter frequency-modulated continuous-wave radar for both remote sensing and wireless identification of sensors. Long reading ranges (up to some decameters) are reached at the expense of poor measurement resolution (typically 10 %). A review of recent experimental results is reported for illustration purposes.