TECHNOLOGY AREA(S): Ground/Sea Vehicles

ACQUISITION PROGRAM: PMS 485, Maritime Surveillance Systems Program Office

OBJECTIVE: Develop and demonstrate an electroactive polymer-based rotary actuator that can survive high levels of shock (5 to 10 g) on any of the three-axis while also being compact (less than 15mm diameter), sealed against seawater at 1000m depth, and operable with low power consumption (less than 0.25A at 12 VDC).

DESCRIPTION: The purpose of this project is to develop and demonstrate the use of electroactive polymer (EAP)-based actuators for Unmanned Undersea and Surface Vehicles (UxV) control surfaces in a high sea-state ocean environment. Unlike conventional surface ships, UxVs are expected to survive and operate in (rather than retreat from) extreme ocean environmental conditions (World Meteorological Organization (WMO) sea-state 7 and above).� The UxV�s control surfaces and actuators must be capable of sustaining high levels of force and acceleration incurred when being tossed and dropped by large waves while also being sufficiently compact and lightweight to be integrated into the platform. For example, if an UxV is operating in a WMO sea-state 8 environment, it could ride atop a 10-meter wave and fall to the ocean surface, which generates forces large enough to damage mechanically conventional control surface actuator components. Conventional commercial actuator components are comprised of a motor and gearing; the gears and associated bearings are especially vulnerable to damage under high shock levels.

A key applicable technology to address this need is the material family generally termed �Electroactive Polymers� (EAP), which change in size or shape upon application of an electrical stimulus or generate a voltage when strain is induced in the material. Best known for use as �artificial muscle� actuators for experimental robots, these materials can potentially sustain large forces such as actuators.

PHASE I: Develop a concept for an EAP-based actuator. Determine the technical feasibility of this concept by modeling the actuator and demonstrating analytically that it should meet performance and durability requirements, based upon the ocean environment and mission duration requirements that will be provided by the Navy. Alternatively, a laboratory scale model proof of concept may be fabricated, tested, and demonstrated. The Phase I Option, if awarded, will include the initial design specifications and capabilities description to build a prototype solution in Phase II. Develop a Phase II plan.

PHASE II: Based upon the Phase I results and the Phase II Statement of Work (SOW), develop, fabricate, and deliver a set of prototype EAP actuators. Install and test these actuators in a Government-provided UxV, with the technical resources of Navy laboratories available to the performer as needed. The Navy will provide the technical specifications and interface documentation required for the integration of the actuators into the target UxV. Complete the design, fabrication, and testing of the functionality of the prototype actuators.� Using lessons learned from laboratory tests, fabricate a set of EAP actuators that will be installed and tested at sea in an UxV. Provide support for testing and performance analysis. Prepare a Phase III development plan to transition the technology for Navy production and potential commercial use.

PHASE III DUAL USE APPLICATIONS: Building on the work of Phase II, design a production-ready set of EAP actuators to be integrated into a specific UxV design identified by the Navy (e.g., Hydroid Remus 600 or Teledyne Webb Slocum sea glider) or by a commercial UxV manufacturer that has teamed with the small business for this project. Develop and build production equipment and processes capable of producing the actuators at a volume and cost that is appropriate with expected demand. Build a set of actuators and perform First Article Testing prior to delivery to the Navy lab or UxV manufacturer. Support integration, lab test, and sea test of the UxV. Based upon test results, revise the design if necessary and deliver the first lot of actuators.

The Navy uses commercial UxV platforms and tethered Remotely Operated Vehicles (ROVs), which are also used by the oil industry and ocean scientists. EAP actuators could be installed into ruggedized variants of commercial UxVs and ROVs. EAP actuators could also provide control surfaces for other sea craft.

REFERENCES:

1. Ashley, Steven. �Artificial Muscles.� Scientific American (October 2003), 289, 52-59, doi:10.1038/scientificamerican1003-52. https://ndeaa.jpl.nasa.gov/nasa-nde/nde-aa-l/clipping/Scientific-Ameican-article-Oct-03.pdf

2. Biggs, J., Danielmeier, K., Hitzbleck, J., Krause, J., Kridl, T., Nowak, S., Orselli, E., Quan, X., Schapeler, D., Sutherland, W. and Wagner, J. �Electroactive Polymers: Developments of and Perspectives for Dielectric Elastomers.� Angewandte Chemie International Edition, 52: 9409�9421. doi:10.1002/anie.201301918. Date of access: 7 March 2017; https://www.researchgate.net/profile/James_Biggs3/publication/251235423_Electroactive_Polymers_Developments_of_and_Perspectives_for_Dielectric_Elastomers/links/004635346f86e08410000000.pdf

3. French, Daniel. �Analysis of Unmanned Undersea Vehicle (UxV) Architectures and an Assessment of UxV Integration into Undersea Applications.� Thesis, Naval Postgraduate School, Sept. 2010. http://www.dtic.mil/dtic/tr/fulltext/u2/a531528.pdf

KEYWORDS: Electroactive Polymer (EAP); Dielectric Elastomer; Artificial Muscles; Actuator; Unmanned Undersea Vehicle (UUV); Unmanned Surface Vehicle (USV)