SITIS Topic Details

Proposals Accepted:  
Program:  SBIR
Topic Number:  A10-151 (Army)
Title:  Deterministic Finishing of Domes with Buried Electromagnetic Structures
Research & Technical Areas:  Materials/Processes
Acquisition Program:  PEO Missiles and Space
 The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), which controls the export and import of defense-related material and services. Offerors must disclose any proposed use of foreign nationals, their country of origin, and what tasks each would accomplish in the statement of work in accordance with section 3.5.b.(7) of the solicitation.
  Objective:  The goal of this topic is to develop a deterministic method for generating a dome with precise location of a buried grid.
  Description:  An approach to dome construction has recently been demonstrated that contains a grid that is buried in optical ceramic material. While this approach makes the dome construction easier, it adds an extra level of difficulty to the dome finishing. There are methods available to deterministically finish the outer surfaces to achieve the correct optical performance but none that can accurately position buried structures during the process. What is required is a way to precisely measure the distance of a buried grid from each surface during the grinding and polishing process.

  PHASE I: Demonstrate a process for precisely measuring the location of a conductive grid buried in a piece of optical ceramic material, such as ALON or spinel, during all phases of grinding and polishing. The measurements will be made normal to the surface and will be used to ensure that only the proper amount of material is removed. Continuous measurement across the surface is not required as long as there is adequate data to calculate the grid location within 1 mil. The process must not depend on the surface quality of the material and must not come in contact with the surface of the work piece or alter material properties. You must demonstrate the ability to precisely measure the location of the grid in samples from various stages of finishing. The samples will be small flats and dome sections. You also need to show how this process would be integrated into the dome manufacturing environment.

  PHASE II: Demonstrate the ability to accurately measure the grid location in an ALON or spinel, 7 inch hemispherical dome through every phase of the dome finishing process. The work done in Phase I must be expanded to demonstrate the ability to measure the distance of the grid from both the concave and convex surface. The process must provide grid depth from any location on the dome. The time for the measurement process must be kept as short as possible, measured in minutes not hours.

  PHASE III: Demonstrate a full production capability incorporating the accurate placement of a grid buried in optical ceramic domes by using the technique(s) developed and refined in Phases I and II. The ability to accurately measure metallic structures embedded in optical ceramics will open the design space for high performance imaging and tracking systems such as those used by the military and in the space industry. There is potential to greatly improve imaging performance by tuning the optics for different potions of the spectrum.

  References:  
1. “Optical characterization of photolithographic metal grids,” Kurt A. Osmer and Mike I. Jones, Proceedings of the SPIE, Tactical Infrared Systems, Vol. 1498, pp.138 -146., October 1991.

2. “Electromagnetic shielding for electro-optical windows and domes,” Clark I. Bright, Proceedings of the SPIE, Window and Dome Technologies and Materials IV, Vol. 2286, pp.388-398, September 1994.

3. "Material for Infrared Windows and Domes," Dan Harris, ISBN 0-8194-3482-5, SPIE Press, 1999

4. "Materials for infrared windows and domes: Properties and performance", Daniel C. Harris, Society of Photo-optical Instrumentation Engineers, Bellingham, August 1999

5. "Tri-mode seeker dome considerations", James C. Kirsch, William, R. Lindberg, Daniel C. Harris, Michael J. Adcock, Tom P. Li, Earle A. Welsh, Rick D. Akins, Proc. SPIE Vol. 5786, p. 33-40, Window and Dome Technologies and Materials IX; Randal W. Tustison; Ed., 18 May 2005

Keywords:  precise measurement, conductive grid, optical ceramic, ALON, spinel, grinding, polishing
Questions and Answers:
Q: 1.) Will the Phase-I "small flats and dome sections" be supplied, or will the proposer be required to obtain them?

2.) In the event the samples are not furnished, will the specifications and suitable manufacturers be identified?

3.) Can you state what is the nominal width of the elements of the "conductive buried grid," and what is the nominal spacing between the elements of the grid?
A: 1.) Will the Phase-I "small flats and dome sections" be supplied, or will the proposer be required to obtain them?

-The flats and dome sections will most likely be supplied to you.

2.) In the event the samples are not furnished, will the specifications and suitable manufacturers be identified?

-Yes.

3.) Can you state what is the nominal width of the elements of the "conductive buried grid," and what is the nominal spacing between the elements of the grid?

-Approximately, the grid line widths are 20 microns and the line spacing is 400 microns.




Q: In order to achieve this goal, is there a preference for one or the other of the following two approaches:

1. developing totally new devices for measuring these materials, or

2. adding novel techniques to existing measurement protocols along with modifications of existing devices?
A: I have no preference. Choose the one that you feel is the best solution. I will base my evaluation on how well it meets the topic, not that it is a new device or an existing protocol.
Q: 1) Will each of these grids end up being part of individually calibrated sensor windows?

2) Is sub micron to micron level repeatability from window assembly to window assembly expected?

2a) If 2) is expected to what tolerance level?

A: 1) Will each of these grids end up being part of individually calibrated sensor windows?

- The topic addresses domes but this technology also applies to windows.
The grid is embedded in the material.

2) Is sub micron to micron level repeatability from window assembly to window assembly expected?

- If you are referring to the gridding processes, they are well controlled but sub micron repeatability has not be verified.

- If you are referring to your measurements, the spec is in the topic.
Repeatability and accuracy are both required.

2a) If 2) is expected to what tolerance level?

- If you are referring to the gridding process, there are several gridding approaches being evaluated. There will be some acceptable variation in the grid but that has not been determined. The important part of the topic is not how well we can make the grid but how well you can measure its location. If a small amount of variation in grid manufacturing is a problem for your approach then I would recommend rethinking the approach.

- If you are referring to your measurements, the spec is covered in the topic. If there is something specific that is unclear please rephrase the question.
As of midnight September 1, questions for solicitations SBIR 10.3 and STTR 10.B will no longer be accepted.
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