In situ tribometer and methods of use

Patent metadata

Field	Value
Publication number	US-10908069-B2
Application number	US-201715597318-A
Country	US
Kind code	B2
Filing date	May 17, 2017
Priority date	Nov 25, 2014
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

Techniques for determining a characteristic of a sample using an atomic force microscope including a cantilever having a probe attached thereto, including positioning the sample within a cell and sliding the probe over a sliding zone of the sample within the cell. Lateral and vertical deformations of the cantilever are detected using the atomic force microscope as the probe is slid over the sliding zone. One or more characteristics are determined based on the detected lateral deformations of the cantilever.

First claim

The invention claimed is:

1. A tribometer for determining one or more characteristics of a surface of a sample, comprising:
an atomic force microscope comprising a cantilever configured to detect lateral and vertical deformations of the cantilever;
a probe attached to an end of the cantilever of the atomic force microscope, wherein the probe comprises a spherical structure;
a cell for holding the sample with the surface comprising a sliding zone to be characterized;
a control unit communicatively coupled with the atomic force microscope and configured to slide the probe over the sliding zone of the sample and determine the one or more characteristics based on a lateral deflection signal of the cantilever generated from the detected deformations of the cantilever, wherein the control unit is configured to simultaneously cause the probe to form an antiwear tribofilm within the sliding zone, image a topography of the sliding zone of the sample, and determine the one or more characteristics without removing the sample from the cell; and
a heating element adapted to maintain the cell at a predetermined temperature.

2. The tribometer of claim 1 , wherein the one or more characteristics include one or more of a friction force or a coefficient of friction, a characteristic corresponding to wear, a characteristic corresponding to adhesion, or a characteristic corresponding to elastic modulus.

3. The tribometer of claim 1 , wherein the cell comprises a liquid cell and the sliding zone of the sample is immersed in a lubricant.

4. The tribometer of claim 1 , wherein the probe is a spherical probe.

5. The tribometer of claim 4 , wherein the probe has a diameter of between 1 μm and 100 μm.

6. The tribometer of claim 1 , wherein the probe is formed from steel.

7. A method for determining one or more characteristics of a surface of a sample using an atomic force microscope including a cantilever having a probe attached thereto, comprising:
positioning the sample within a cell;
sliding the probe over a sliding zone of the surface of the sample within the cell, wherein the probe comprises a spherical structure;
detecting lateral and vertical deformations of the cantilever using the atomic force microscope as the probe is slid over the sliding zone;
determining one or more characteristics of the sliding zone based on the detected lateral deformations of the cantilever;
maintaining the cell at a predetermined temperature using a heating element; and
simultaneously forming an antiwear tribofilm within the sliding zone, imaging a topography of the sliding zone of the sample, and determining the one or more characteristics without removing the sample from the cell.

8. The method of claim 7 , wherein the one or more characteristics of the sliding zone includes one or more of a coefficient of friction, a characteristic corresponding to wear, a characteristic corresponding to adhesion, or a characteristic corresponding to elastic modulus.

9. The method of claim 7 , wherein the cell comprises a liquid cell, further comprising:
immersing the sliding zone of the sample in a lubricant.

10. The method of claim 7 , wherein the probe is a spherical probe.

11. The method of claim 10 , wherein the probe has a diameter of between 1 μm and 100 μm.

12. The method of claim 7 , wherein the probe is formed from steel.

Assignees

• Univ Pennsylvania

Inventors

• Carpick Robert W
• Gosvami Nitya Nand

Classifications

• G01Q60/26 Primary

  Friction force microscopy · CPC title

• G01Q30/14

  Liquid environment · CPC title

• G01Q70/10

  Shape or taper · CPC title

• G01N19/02 Primary

  Measuring coefficient of friction between materials {(testing of tyres G01M17/02; determinations of friction coefficient used in vehicle braking or traction control systems B60T8/172)} · CPC title

• G01Q60/24

  AFM [Atomic Force Microscopy] or apparatus therefor, e.g. AFM probes · CPC title