Method and apparatus for characterizing materials by using a mechanical resonator

A method for monitoring a change in a property of a liquid composition, the method comprising:

• placing the mechanical resonator in the liquid composition such that at least a portion of the mechanical resonator is submerged in the liquid composition;
• applying a variable frequency input signal to a measurement circuit coupled with the mechanical resonator to oscillate the mechanical resonator;
• varying the frequency of the variable frequency input signal over a predetermined frequency range to obtain a frequency-dependent resonator response of the mechanical resonator;
• determining the property of the liquid based on the mechanical resonator response;
• repeating the applying, varying, and determining steps over time;
• and
• monitoring over time a change in the mechanical resonator response reflecting the change in property of the liquid composition.

An apparatus for measuring a property of a fluid composition, comprising:

• a tuning fork resonator;
• means for containing the fluid composition;
• a measurement circuit coupled with said tuning fork resonator, said measurement circuit having a signal generator for generating a variable frequency input signal to cause said tuning fork to oscillate;
• and
• a receiver coupled to the measurement circuit to output a frequency response of said tuning fork resonator.

A method for measuring a property of a plurality of liquid compositions using a plurality of mechanical resonators, the method comprising:

• providing an array of sample wells;
• placing each of said plurality of liquid compositions in a separate sample well;
• placing at least one of said plurality of mechanical resonators into at least one of said sample wells such that at least a portion of the mechanical resonator is submerged in its associated liquid composition;
• applying a variable frequency input signal to a measurement circuit coupled with at least one of said plurality of mechanical resonators to oscillate said at least one mechanical resonator in its associated liquid composition;
• varying the frequency of the variable frequency input signal over a predetermined frequency range to obtain a frequency-dependent resonator response of the at least one mechanical resonator;
• and
• determining the property of the liquid based on the mechanical resonator response to measure a property of each liquid composition.

A method for measuring a property of a liquid composition flowing through a conduit, the method comprising:

• placing a mechanical resonator in the conduit such that at least a portion of the mechanical resonator will be surrounded by the fluid composition as the fluid composition flows through the conduit;
• applying a variable frequency input signal to a measurement circuit coupled with the mechanical resonator to oscillate the tuning fork resonator;
• varying the frequency of the variable frequency input signal over a predetermined frequency range to obtain a frequency-dependent resonator response of the mechanical resonator;
• and
• determining the property of the fluid composition based on the mechanical resonator's response.