Creating a Near Perfect Flat Surface: Difficult but Possible

  • Thread starter Thread starter sid_galt
  • Start date Start date
  • Tags Tags
    Flat Surface
Click For Summary

Discussion Overview

The discussion revolves around the feasibility of achieving a near perfect flat surface with a roughness of 1-10 nm. Participants explore the challenges associated with achieving such precision in surface flatness, particularly in the context of materials and applications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the possibility of achieving a near perfect flat surface with a roughness of 1-10 nm and asks about the difficulty involved.
  • Another participant cites carbon face seals as an example of extremely flat surfaces, mentioning specific flatness measurements and suggesting that discussing surfaces in nanometers may lead to macroscopic issues.
  • A participant claims to routinely produce samples with a flatness and parallelism of less than 100 nm over a specific area, noting the challenges and costs associated with improving flatness.
  • There is a repeated inquiry about the material, size of the active area, and budget related to achieving the desired flatness.
  • One participant describes their polishing process for Gallium Arsenide, emphasizing the need for low tolerance due to the measurement of quantum transport phenomena in quantum well structures.

Areas of Agreement / Disagreement

Participants express varying views on the feasibility and difficulty of achieving the desired surface flatness, with no consensus reached on the possibility of achieving 1-10 nm roughness. The discussion includes both technical insights and personal experiences, indicating a range of perspectives on the topic.

Contextual Notes

The discussion highlights the dependence on specific materials and applications, as well as the challenges related to polishing techniques and monetary investment. There are unresolved questions regarding the exact requirements for achieving the proposed surface flatness.

sid_galt
Messages
503
Reaction score
1
Is it possible to get a near perfect flat surface with the roughness no more than 1-10 nm at any point?

If it is, then how difficult is it?
 
Engineering news on Phys.org
The surface of carbon face seals are extremely flat with incredibly smooth surface finishes. The flatness callouts I am used to seeing are .000035" or about three helium light bands. That is about the best I have ever seen. I think you'd be running into macroscopic troubles when talking about surfaces in terms of nanometers.

Here is a reference for you on the topic in regards to sealing surfaces and pumps:
http://www.mcnallyinstitute.com/Charts/flatness_readings.html

For those interested, The Mcnally Institute website has some fantastic information regarding pumps and seals. It is a very valuable resource!
 
We routinely make samples that have a flatness and parallelism of less than 100nm over an area of about 10 sq. mm. The polishing process is both tricky and painful (in addition to being material specific), and getting a better flatness would require a substantially greater monetary investment.

What material are you working with, and what is the size of the active area that you want flat ? And what's your budget ?
 
Gokul43201 said:
What material are you working with, and what is the size of the active area that you want flat ? And what's your budget ?

I am not working on any material. I was just curious.
 
Gokul43201 said:
We routinely make samples that have a flatness and parallelism of less than 100nm over an area of about 10 sq. mm.

What componds do you polish with? Is this by hand? What is the purpose of the flatness/finish tolerance being so darned low (applications)?
 
The polishing is done in several stages, mostly by hand, with the assistance of a polishing jig. The polishing compound is very specific to the material that we are polishing - Gallium Arsenide. Why do we need this low a tolerance ? Because we measure quantum transport phenomena in GaAs quantum well structures where the well spacing in just few tens of nanometers. This is fundamental research and has no applications as of now.
 

Similar threads

Undergrad Theoretically, can perfectly flat spacetime exist in the Universe?
  • · Replies 31 ·
2
Replies
31
Views
3K
Can a glass of water be filled to its edge?
  • · Replies 42 ·
2
Replies
42
Views
8K
Freon filled balloons go flat QUICKLY! Why?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Measuring difference in Exercising in a Flat Surface vs one with Slope
  • · Replies 5 ·
Replies
5
Views
2K
High School Size of universe - rewinding big bang versus "flat" universe
  • · Replies 54 ·
2
Replies
54
Views
6K
Undergrad Flat surface to curved surface
  • · Replies 4 ·
Replies
4
Views
3K
Tensile Test Results: Adhesion of Tape to Plastic Surface
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Is it possible to have "ideal surface" whose highest peak is ~1 nm?
  • · Replies 13 ·
Replies
13
Views
2K
High School Vacuum surface area balance and force
  • · Replies 4 ·
Replies
4
Views
2K
How Do You Calculate Pressure and Flow for an Air Float Conveyor?
  • · Replies 3 ·
Replies
3
Views
2K