High throughput microbalance and methods of using same
View Patent ↗A method and apparatus for measurement of mass of small sample sizes. The method and apparatus is particularly adapted for providing microbalance measurement of solid materials as part of a combinatorial research program. The method and apparatus contemplate monitoring the response of a resonator holding a sample and correlating the response with mass change in the samples.
1. A method for controlling a process including polymer particulate, the method comprising
contacting a mechanical resonator with polymer particulate in a chamber enclosing the polymer particulate, the mechanical resonator being a flexural resonator and being contacted with the polymer particulate in the presence of a flow of gas in the chamber,
controlling one or more environmental conditions of the chamber,
measuring the mass or mass change of the polymer particulate at a first time by applying an input signal to the mechanical resonator, monitoring a response of the mechanical resonator to the input signal, the response being represented by a response signal of the mechanical resonator, and processing the response signal to determine the mass or the mass change of the polymer particulate at the first time,
varying one or more of the controlled environmental conditions in the chamber after the first time, and
measuring the mass or mass change of the polymer particulate at a second time after varying the one or more of the controlled environmental conditions by applying an input signal to the mechanical resonator, monitoring a response of the mechanical resonator to the input signal, the response being represented by a response signal of the mechanical resonator, and processing the response signal to determine the mass or the mass change of the polymer particulate at the second time.
2. The method of claim 1 wherein the mass or mass change of the polymer is measured over time.
3. The method of claim 1 wherein the mechanical resonator is contacted with polymer in the presence of a flow of gas in the chamber.
4. The method of claim 1 wherein the polymer is a polymer particulate.
5. The method of claim 1 wherein the polymer is an irregularly-shaped polymer particulate.
6. The method of claim 1 wherein the polymer is a polymer blend.
7. The method of claim 1 wherein the chamber encloses the polymer.
8. The method of claim 1 wherein the temperature of the chamber is controlled.
9. The method of claim 1 wherein the pressure of the chamber is controlled.
10. The method of claim 1 wherein the temperature and the pressure of the chamber are controlled.
11. The method of claim 1 wherein the polymer is monitored at the first time and the second time to measure the mass or mass change of the polymer at the first time and the second time, by a method comprising actuating the mechanical resonator, monitoring a response of the actuated mechanical resonator, and correlating the monitored response to the mass or the mass change of the polymer.
12. The method of claim 11 wherein the mechanical resonator is actuated by applying an input signal to the mechanical resonator.
13. The method of claim 1 wherein the polymer is monitored at the first time and at the second time by a method comprising
applying an input signal to the mechanical resonator,
monitoring a response of the mechanical resonator to the input signal, the response being represented by a response signal of the mechanical resonator, and
processing the response signal to determine the mass or the mass change of the polymer.
14. The method of claim 1 wherein the mass or mass change of the polymer is measured in less than one minute.
15. The method of claim 1 wherein the polymer is monitored at the first time in less than one minute and the polymer is monitored at the second time in less than one minute.
16. The method of claims 1 or 11 wherein the mass or mass change of the polymer is measured at the first time in less than one minute and the mass or mass change of the polymer is measured at the second time in less than one minute.
17. The method of claims 1 or 11 wherein the mass or mass change of the polymer is measured by a method comprising
applying an input signal to the mechanical resonator,
monitoring a response of the mechanical resonator to the input signal, the response being represented by a response signal of the mechanical resonator, and
processing the response signal to determine the mass or the mass change of the polymer.
18. The method of claims 1 or 11 wherein the mass or mass change of the polymer is measured by a method comprising
applying a variable frequency input signal to the mechanical resonator,
varying the frequency of the variable frequency input signal over a predetermined frequency range,
obtaining a frequency-dependent response of the mechanical resonator to the input signal, the response being represented by a response signal of the mechanical resonator, and
processing the response signal to determine the mass or the mass change of the polymer.
19. The method of claim 1 wherein the mechanical resonator is a tuning fork resonator.
20. The method of claim 1 wherein the mechanical resonator is a piezoelectric resonator.
21. The method of claim 1 wherein the mechanical resonator is a flexural resonator, and the flexural resonator is actuated by applying an input signal having a frequency of less than about 1 MHz.
22. The method of claim 1 wherein the mechanical resonator is a flexural piezoelectric resonator, and the flexural piezoelectric resonator is actuated by applying an input signal having a frequency of less than about 500 kHz.
23. The method of claims 1 or 11 wherein the mass or mass change of the polymer is measured using measurement hardware comprising a plurality of mechanical resonators in an array, each of the plurality of mechanical resonators being adapted for contacting polymer in the chamber.
24. The method of claims 1 or 11 wherein the mass or mass change of the polymer is measured using measurement hardware comprising a plurality of mechanical resonators in an array, each of the plurality of mechanical resonators being adapted for contacting polymer in the chamber, and using software for controlling the measurement hardware, the software being programmed with location information for the plurality of mechanical resonators.