TECHNOLOGY AREAS: Materials/Processes

ACQUISITION PROGRAM: PEO Subs, PMS-450, Virginia Program Office

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 objective of the topic is to develop and demonstrate manufacturing technology for metamaterials that can be used to construct spherical shells that pass acoustic radiation without backscattering and fill in the shadow zone behind the incident field.

DESCRIPTION: Through acoustic scattering theory, Cummer et. al. derived the mass density and bulk modulus of a spherical shell that can eliminate scattering from an arbitrary object in the interior of the shell: in other words, an acoustic cloaking shell. It requires an anisotropic mass density with principal axes in the spherical coordinate directions and a radially-dependent bulk modulus. Techniques to manufacture these exotic "metamaterials" are required to advance the theory and applications of acoustic cloaking technology.

PHASE I: Investigate the concept of using metamaterials to provide acoustic cloaking of objects at frequencies of interest to the U.S. Navy. Summarize with a final report describing the properties of acoustic cloaking metamaterials and a concept for manufacturing them.

PHASE II: Develop a model for materials to exhibit cloaking properties at Naval acoustic frequencies and fabricate a laboratory proof of concept demonstrating the ability to manufacture metamaterials in small lots.

PHASE III: Clearly identify and describe the expected transition of the product/process/service within the government as a result of the Phase II, in which the small business will participate under a Phase III.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: The commercial potential of acoustic cloaking material includes suppliers of sound control materials and room designers who want to use advanced materials to control sound propagation within airports, subway and railway stations, conference rooms, classrooms, offices, homes and concert halls.

REFERENCES:
1. J. B. Pendry, D. Schurig, and D. R. Smith, Science 312, 1780 (2006).

2. D. Schurig, J. B. Pendry, and D. R. Smith, Opt. Exp. 14, 9794 (2006).

3. D. A. B. Miller, Opt. Exp. 14, 12457 (2006).

4. H. Chen, B.-I.Wu, B. Zhang, and J. A. Kong, Phys. Rev. Lett. 99, 063903 (2007).

KEYWORDS: Metamaterials, acoustic cloaking, cloaking shells, submarines.

** TOPIC AUTHOR (TPOC) **

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