Super high sensitive plate acoustic wave humidity sensor based on graphene oxide film.

The changes of density and elastic modules due to water vapor adsorption are measured for graphene oxide film at room temperature. Dominant mechanism for acoustic wave humidity sensing by the film is shown to be related with variation of its electric conductivity. Basing on the data, super high sensitive humidity sensor employing high-order Lamb wave with large coupling constant, standard lithium niobate plate, and graphene oxide sorbent film is developed.

Liquid sensor based on a piezoelectric lateral electric field-excited resonator.

The influence of viscous and conducting liquid on the characteristics of a piezoelectric lateral electric field-excited resonator based on the X-cut lithium niobate plate has been investigated. It has been found that the contact of a free surface of such resonator with conducting or viscous liquid leads to the substantial variation of its electrical impedance/admittance. The analysis has shown the modulus of electrical impedance or admittance at any frequency near the parallel or series resonance to be a parameter unambiguously associated with the conductivity or the viscosity.

Biological sensor based on a lateral electric field-excited resonator.

This paper describes a biological sensor based on a lateral electric field-excited resonator using an X-cut lithium niobate plate. Its potential was shown through the example of biological interaction between bacterial cells and specific bacteriophages. The detection was based on the analysis of the measured real and imaginary parts of electrical impedance for a resonator loaded by the biological suspension under study.

Elastic and viscous properties of nanocomposite films based on low-density polyethylene.

The physical properties of nanocomposite materials which contain nanoparticles of metals and their compounds stabilized within a polymeric dielectric matrix are currently being studied. These materials show a low acoustic impedance, resulting in their use as low-perturbing substrates for thin piezoelectric plates, as well as matching and damping layers for bulk acoustic wave devices. Mechanical properties of the materials which contain various Fe and Fe2O3 nanoparticle concentrations are experimentally defined in the paper.