Abstract: Propagation of ultrasound through a porous body saturated with liquid generates electric response. This electro-acoustic effect is called “seismoelectric current”, whereas reverse version, when electric field is driving force, is “electroseismic current”. It is possible to measure seismoelectric current with existing electro-acoustic devices, which had been designed for characterizing liquid dispersions. Such versatility allows calibration of said devise using dispersion and then applying it for characterizing porous body. In general, magnitude of seismoelectric current depends on porosity, pore size, zeta potential of pore surfaces and elastic properties of matrix. It is possible to adjust conductivity of liquid for simplifying these dependences. For instance, liquid with high ionic strength causes double layers become thin comparing to the pore size, which eliminates dependence of said currents on pore size. We suggest using such case for characterizing porosity.

Abstract: Propagation of ultrasound through a porous body saturated with liquid generates electric response. This electro-acoustic effect is called “seismoelectric current”, whereas reverse version, when electric field is driving force, is “electroseismic current”. It is possible to measure seismoelectric current with existing electro-acoustic devices, which had been designed for characterizing liquid dispersions. Such versatility allows calibration of said devise using dispersion and then applying it for characterizing porous body. In general, magnitude of seismoelectric current depends on porosity, pore size, zeta potential of pore surfaces and elastic properties of matrix. It is possible to adjust conductivity of liquid for simplifying these dependences. For instance, liquid with high ionic strength causes double layers become thin comparing to the pore size, which eliminates dependence of said currents on pore size. We suggest using such case for characterizing porosity.

Abstract: Propagation of ultrasound through a porous body saturated with liquid generates electric response.

Abstract: A method is described which applies Acoustic Spectrometry to characterize both the particle size distribution and micro-rheological properties of the structured concentrated dispersions. It suggests to model the structured dispersion as a collection of the spherical particles which are connected together with flexible strings. Oscillation of these strings creates an additional energy dissipation which contributes to the total attenuation. This dissipation is dependent on the second virial coefficient characterizing the flexibility of the strings. It is shown that the value of the second virial coefficient can be calculated from the measured attenuation spectra either for known particle size or together with particle size as adjustable parameter.

Abstract: The applicant describes a new method of generating directed motion of the liquid in the microfluidic device by applying “un-balanced” AC electric field for generating electroosmosis and related hydrodynamic flow in the chamber with any symmetry of the elements, including spherical or cylindrical symmetry, and any relative position of these elements. Direction of the flow depends on the phase of the “un-balanced” electric field, which opens a simple way to operate flow and create a desirable flow pattern.

Abstract: A method is described which applies Acoustic Spectrometry to characterize both the particle size distribution and mechanical properties of the soft particles in concentrated dispersed systems. It is shown that compressibility of the soft particles can be calculated from the measured sound speed using well-known Wood expression. The value of the thermal expansion coefficient can be calculated from the measured attenuation spectra either for known particle size or together with particle size as adjustable parameter.

Abstract: A “coupled phase model” is used to characterize the motion induced by a sound wave of a particle relative to its dispersion medium. A Kuvabara cell model is used to describe the hydrodynamic effects, whereas a Shilov-Zharkikh cell model is used to characterize electrokinetic effects. A different approach for interpreting the experimental data is described in which the electroacoustic sensor is treated as a transmission line with various energy losses due to the reflection and sound attenuation. The experimental output is also expressed as a loss, namely the ratio of the Colloid Vibration Current to the gradient in the acoustic pressure, and is computed by subtracting all other known losses from the total loss of the electroacoustic sensor. These other energy losses can be either calculated or measured directly using reflected pulses.

Abstract: A device is described which combines Acoustic and Electroacoustic spectrometers to characterize both particle size distribution and zeta potential for concentrated dispersed systems.The Acoustic Spectrometer measures both attenuation and sound speed for multiple frequencies using each measurement to help optimize and correct the other. The attenuation spectra is used to calculate particle size.The Electroacoustic Spectrometer measures Colloid Vibration Current (CVI), correcting the measured value using attenuation and sound speed data from the Acoustic Spectrometer. The Colloid Vibration Current is used to calculate zeta potential taking into account the particle size calculated from the acoustic measurement as well as particle interaction.Sound speed and multiple frequency CVI measurement provide additional experimental data to check the validity of the data.