Vapor phase low molecular weight lubricants

• US 6,004,912 A
• Filed: 06/05/1998
• Issued: 12/21/1999
• Est. Priority Date: 06/05/1998
• Status: Expired due to Term

• Current Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Original Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Inventors: Gudeman, Christopher Scott
• Primary Examiner(s): McAvoy, Ellen M.
• Application Number:
  US09/092,220
• Time in Patent Office: 564 Days
• Field of Search: 134/31, 134/37, 508/577, 508/583
• US Class Current: 508/577
• CPC Class Codes: C10M 171/00 Lubricating compositions characterised by purely physical criteria, e.g. containing as base-material, thickener or additive, ingredients which are characterised exclusively by their numerically specified physical properties, i.e. containing ingredients which are physically well-defined but for which the chemical nature is either unspecified or only very vaguely indicated chemically defined ingredients C10M101/00 - C10M169/00; petroleum fractions C10M101/02, C10M121/02, C10M159/04

Abstract

An improved micro machine has at least a first element which is moveable relative to a second element such that the first and second elements can be in contact with each other. The contacting portions of both the first and second elements are protected with a long-lasting lubricant to prevent the elements from sticking or adhering to each other. The lubricant is a polar low molecular weight compound preferably applied as a vapor. This class of low molecular weight lubricants consists of acetone, ethanol, ethylene glycol, glycerol, isopropanol, methanol, and water. According to the disclosure a lubricant has a low molecular weight if its molecular weight is less than ˜100 amu, or has a vapor pressure ≧5 Torr at room temperature. The preferred micro machine is a GLV wherein the bottom of the deformable ribbon contacts the landing electrode when the reflector is in a down position (close to the substrate). By applying any one of these low molecular weight lubricants in their gas phase to the contacting portions of the deformable ribbon and the landing electrode, these contacting portions will not weld, adhere, or stick together over a period of cycles. The lubricant is applied by bubbling an inert gas through a liquid reservoir of the lubricant and flowing the resultant vapor over the micro machine.

Claims

1. A method of lubricating a micro machine comprising the step of applying a lubricant to the micro machine wherein the lubricant is a compound having a permanent electric dipole moment.

2. The method according to claim 1 wherein the lubricant is selected from the group consisting of acetone, ethanol, ethylene glycol, glycerol, isopropanol, methanol, and water.

3. The method according to claim 1 wherein the lubricant is a vapor.

4. The method according to claim 1 wherein the lubricant is a polar low molecular weight vapor compound.

5. The method as claimed in claim 4 wherein the polar low molecular weight vapor compound is water in a gaseous physical state.

6. The method as claimed in claim 4 wherein the polar low molecular weight vapor compound is acetone in a gaseous physical state.

7. The method as claimed in claim 4 wherein the polar low molecular weight vapor compound is ethanol in a gaseous physical state.

8. The method as claimed in claim 4 wherein the polar low molecular weight vapor compound is ethylene glycol in a gaseous physical state.

9. The method as claimed in claim 4 wherein the polar low molecular weight vapor compound is glycerol in a gaseous physical state.

10. The method as claimed in claim 4 wherein the polar low molecular weight vapor compound is isopropanol in a gaseous physical state.

11. The method as claimed in claim 4 wherein the polar low molecular weight vapor compound is methanol in a gaseous physical state.

12. The method as claimed in claim 4 wherein the lubricant has a relative vapor pressure of at least 8%.

13. A method of making a micro machine comprising the steps of:

a. forming a ribbon element above a substrate wherein the ribbon element and the substrate include facing surfaces and at least one of the facing surfaces is initially a rough surface;

b. appalling a lubricant on one of the facing surfaces, wherein the lubricant is selected from the group consisting of acetone, ethanol, ethylene glycol, glycerol, isopropanol, methanol, and water; and

c. smoothing the rough surface by repeatedly contacting the facing surfaces together with the lubricant between the facing surfaces.

14. A method of lubricating a micro machine comprising the steps of:

a. flowing an inert gas through a liquid reservoir of a lubricant for forming a lubricant rich gas; and

b. flooding a partially sealed vessel containing the micro machine with the lubricant rich gas wherein the lubricant is a polar low molecular weight compound.

15. A method of lubricating a micro machine comprising the steps of:

a. flowing an inert gas through a liquid reservoir of a lubricant for forming a lubricant rich gas wherein the lubricant is a polar low molecular weight vapor compound;

b. combining the lubricant rich gas with an inert gas for forming a mixed gas; and

c. flooding a partially sealed vessel containing the micro machine with the mixed gas.

16. A method of lubricating a micro machine comprising the steps of:

a. flowing an inert gas through a liquid reservoir of a lubricant for forming a lubricant rich gas;

b. combining the lubricant rich gas with an inert gas for forming a mixed gas;

c. flooding a vessel containing the micro machine with the mixed gas to a predetermined vapor pressure of the mixed gas, wherein the predetermined vapor pressure is at least 8%; and

d. sealing the vessel to maintain the predetermined vapor pressure of the mixed gas.

17. A modulator for modulating an incident beam of light comprising:

a. a plurality of elongated elements, each element having a first end and a second end and a light reflective planar surface, wherein the elements are grouped into a first group and a second group such that the elements of the first group are interdigitated with the elements of the second group, the elements being arranged parallel to each other;

b. means for suspending the elements of the first group and the second group by their ends;

c. a substrate positioned parallel to the elongated elements;

d. means for electrically coupling all the elongated elements of the first group in each row together;

e. means for electrically coupling all the elongated elements of the second group in each row together;

f. means for applying a first bias voltage to the first group and mearns for applying a second bias voltage to the second group such that the reflective surfaces are substantially coplanar and in a first plane such that the incident beam of light is reflected;

g. means for selectively deflecting the elements of the first group perpendicular to the first plane toward a second plane which is parallel to the first plane and into contact with the substrate such that the incident beam of light is diffracted; and

h. a lubricant rich vapor between the elements of the first group and the substrate.

18. The modulator according to claim 17 wherein the lubricant is selected from the group consisting of acetone, ethanol, ethylene glycol, glycerol, isopropanol, methanol, and water.

19. A micro-mechanical device for preventing degradation in performance due to welding, the device comprising:

a. a first element;

b. a second element selectively moveable relative to the first element wherein a portion of the first element is selectively in contact with a portion of the second element thereby forming a contact portion; and

c. a film of a polar low molecular weight gaseous phase lubricant applied in a gaseous state to at least the contact portion.

20. The micro-mechanical device according to claim 19 wherein the lubricant is selected from the group consisting of acetone, ethanol, ethylene glycol, glycerol, isoprdpanol, methanol and water.