High throughput microbalance and methods of using same

• US 20050166679A1
• Filed: 03/28/2005
• Published: 08/04/2005
• Est. Priority Date: 05/24/2002
• Status: Active Grant

• Current Assignee: Meas France
• Original Assignee: Symyx Technologies Incorporated (Dassault Systemes SA)
• Inventors: Spitkovsky, Mikhail, Carlson, Eric D., Matsiev, Leonid, Kolosov, Oleg, Gallipeo, John, Mazzola, Laura T.
• Granted Patent: US 7,207,211 B2
• Time in Patent Office: Days
• US Class Current: 73/579
• CPC Class Codes: B01J 2219/00689 using computers
• CPC Class Codes: B01J 2219/00707 separated from the reactor apparatus
• CPC Class Codes: G01G 3/13 having piezoelectric or piezoresistive properties
• CPC Class Codes: G01N 2291/0257 with a layer containing at least one organic compound
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• CPC Class Codes: G01N 33/15 Medicinal preparations ; Physical properties thereof, e.g. dissolubility
• CPC Class Codes: G01N 5/045 for determining moisture content

Abstract

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.

Claims

1. A method for measuring mass or mass change of a polymer, the method comprising

contacting a mechanical resonator with polymer in a chamber, the polymer being a solid or semi-solid polymer particulate or a solid or semi-solid polymer film,

controlling one or more environmental conditions of the chamber,

measuring the mass or mass change of the polymer 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.

4. The method of claim 1 wherein the mass or mass change of the polymer is measured over time.

5. The method of claims 1 or 2 wherein the mechanical resonator is contacted with polymer in the presence of a flow of gas in the chamber.

6. The method of claims 1 or 2 wherein the polymer is a polymer particulate.

7. The method of claims 1, 2 or 3 wherein the polymer is an irregularly-shaped polymer particulate.

8. The method of claims 1 or 2 wherein the polymer is a polymer film.

9. The method of claims 1 or 2 wherein the polymer is a polymer film comprising a non-uniform layer of polymer.

10. The method of claims 1, 2 or 3 wherein the polymer is a polymer blend.

11. The method of claims 1, 2 or 3 further comprising placing the polymer on the mechanical resonator by contacting the mechanical resonator with the polymer in the chamber.

12. The method of claims 1 or 2 wherein the chamber encloses the polymer.

13. The method of claims 1, 2 or 3 wherein the temperature of the chamber is controlled.

14. The method of claims 1, 2 or 3 wherein the pressure of the chamber is controlled.

15. The method of claims 1, 2 or 3 wherein the temperature and the pressure of the chamber are controlled.

17. The method of claims 1, 2 or 16 wherein the mechanical resonator is actuated by applying an input signal to the mechanical resonator.

20. The method of claim 1 wherein the mass or mass change of the polymer is measured in less than one minute.

23. The method of claims 1, 3 or 16 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.

24. The method of claims 1, 3 or 16 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.

25. The method of claims 1 or 2 wherein the mechanical resonator is a flexural resonator.

26. The method of claims 1 or 2 wherein the mechanical resonator is a torsional resonator.

27. The method of claims 1, 2 or 3 wherein the mechanical resonator is a tuning fork resonator.

28. The method of claims 1, 2 or 3 wherein the mechanical resonator is a piezoelectric resonator.

29. The method of claims 1, 2 or 3 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.

30. The method of claims 1, 2 or 3 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.

33. The method of claims 1, 3 or 16 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.

34. The method of claims 1, 3 or 16 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.

2. A method for controlling a process including a polymer, the method comprising

contacting a mechanical resonator with polymer in a chamber, the polymer being a solid or semi-solid polymer particulate or a solid or semi-solid polymer film,

controlling one or more environmental conditions of the chamber,

monitoring the polymer at a first time by actuating the mechanical resonator and monitoring a first response of the actuated mechanical resonator,

varying one or more of the controlled environmental conditions in the chamber after the first time, and

monitoring the polymer at a second time after varying the one or more environmental conditions in the chamber by actuating the mechanical resonator, and monitoring a second response of the actuated mechanical resonator.

16. The method of claim 2 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.

18. The method of claim 2 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.

19. The method of claim 2 wherein the polymer is monitored at the first time and at the second time 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 particulate.

21. The method of claim 2 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.

22. The method of claims 3 or 16 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.

31. The method of claim 2 wherein the polymer is monitored 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.

32. The method of claim 2 wherein the polymer is monitored 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.

3. 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.