Air force 17. 1 Small Business Innovation Research (sbir) Phase I proposal Submission Instructions

The custom coatings developed in this program should be compatible with existing coating deposition methods, such as pneumatic high volume low pressure sprayers and ambient temperature curing. Coatings should achieve a total (diffuse and specular) reflectivity of 95% (threshold) >98% (objective) across as broad a spectral range as possible, specifically including Vis and SWIR spectral regions. Beyond processing requirements, the coatings must be robust, providing corrosion protection, mechanical durability, UV stability, thermal stability, and other properties typical of high performance aerospace grade paint formulations. It is anticipated that existing commercial primer systems will suffice in attaining the desired optical properties and not require redevelopment; however if the offeror thinks that primer development is necessary, then it should be proposed. While a variety of molecular structures are tenable for processing and durability requirements, the structure should be designed and selected to minimize direct absorption of the light by the polymer. As such, the anticipated solutions are polyurethanes, polysulfides, and epoxy based polymers; however other molecular structures may prove successful in attaining the given performance. It is anticipated that the offerors will employ an existing binder system and develop a novel formulation of fillers to achieve the necessary total reflectance values. Offerors are encouraged to reduce or eliminate hazardous VOCs, hexavalent chromium, and strontium chromate from any formulations.

Generally, the goal is to develop a coating in compliance with MIL-PRF-32239 (available at http://quicksearch.dla.mil/), with the exception of those elements of the specification relating to maximum infrared reflectance. The coating developed need not achieve every performance metric at the outset, but over the course of all three phases of the program coatings are expected to be capable of the performance metrics outlined in the specification.

No government facilities are anticipated in the performance of this effort. Offerors are encouraged to source their own metallic and graphite composite substrate coupons representative of high performance aerospace structures; though government assistance in procuring such coupons may be proposed. It is encouraged that the offeror anticipate necessary quality control metrics and plan for the ability to execute reflectivity measurements quickly and economically during the course of the program.

PHASE I: Formulate coating, apply to test coupons, measure and maximize total reflectance values. Create and deliver raw material sample (>= 1 liter) capable of being spray deposited. Deliver residual test coupons to government. Assess and document processability of the material, including identifying preliminary quality metrics and process controls.

PHASE II: Further refine formulation to maximize total reflectance. Assess and document durability of the material, including thermal exposure, UV exposure, solvent compatibility, and mechanical durability. Deliver (>= 10 liters) of material for assessment by AF representatives. Assess and document processing windows, deposition parameters, adhesion, and metrics for quality assurance. Deliver residual test coupons to government.

PHASE III DUAL USE APPLICATIONS: Further advance manufacturing maturity and production capacity. Finalize understanding of adhesion, compatibility, durability, aging, and quality control. Commercial applications include energy efficient solar paints and thermal control applications. Military applications include the AFLCMC platforms, including WI.

REFERENCES:

1. Philips-Invernizzi B, Dupont DE, Caza´ CA, Bibliographical review for reflectance of diffusing media, Optical Engineering, 2001, 40 (6):1082-92.

2. Kinoshita, S. & Yoshida, A, "Investigating performance prediction and optimization of spectral solar reflectance of cool painted layers," Energy and Buildings, 2016, 114:214-220.

3. S. Wijewardane, D.Y. Goswami, “A review on surface control of thermal radiation by paints and coatings for new energy applications,” Renewable and Sustainable Energy Reviews, 2012, 16(4):1863-73.

4. Raman, A.P., Anoma, M.A., Zhu, L., Rephaeli, E., Fan, S., "Passive radiative cooling below ambient air temperature under direct sunlight", Nature, 2014, 515:540.

KEYWORDS: backscattering, diffuse reflectance, high volume low pressure spray, paint, polymer, polysulfide, polyurethane, thermal control

TECHNOLOGY AREA(S): Materials/Processes

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.

OBJECTIVE: Mature material synthesis and metrology for high-permeability materials to enable magnetic high-impedance ground planes. Mate materials with models to predict RF antenna. Demonstrate broadband (HF to UHF), efficient, conformal RF antenna.

DESCRIPTION: RF signal collection and wireless communications across many different frequency regimes require underlying antenna technology that is capable of operating over extremely broad frequency ranges, typically from HF (~2 MHz), to UHF (~3 GHz), often with the added desire to have such an antenna be conformal for a host of reasons, including non-protruding surfaces and reduced drag.

Traditional electronic circuits and radiating elements (aka antennas) face significant challenges in providing high radiation efficiency across this wide bandwidth, let alone in also attempting to meet compact and conformal platform requirements. Indeed, for an antenna with a longest dimension that fits within a sphere of radius a, the Efficiency Bandwidth Product (EBWP)[1] cannot exceed EBWP = 1/Q_rad ~ (2*Pi*a/lambda)^3. Here, Q_rad is the ratio of the reactive energy stored in the near field of the antenna per cycle to the power radiated to the far field by the antenna. Further, for antennas restricted to a surface mount—as is typically the case when employing an electrical antenna against a metal ground plane to meet a conformal requirement—this limit is further reduced by a factor of 4. A second challenge facing broadband antennas occurs for electrical circuit antenna designs implemented against low (electrical) impedance environments. Whether mounting such to sides of cars, against walls, or integrated onto an airframe, the electrical currents induced by such a conformal metal antenna result in image currents that oppose the radiating current. As the far field radiated power by such an antenna carrying a current I is given by P_rad=(I)^2 * R_rad/2, the decrease in radiation resistance from such opposing currents further drops the EBWP by the same factor. Hence, conventional electrical circuits mounted to dielectric/metal ground planes force severe choices between achieving conformal design, large bandwidth of operation, and radiating efficiency.

Recently, new conformal antenna designs have been demonstrated utilizing magnetic circuits [2, 3]. In these experiments, high magnetic impedance substrates, such as NiZn (a traditional anechoic chamber tile material for RF damping), Permalloy, and similar high µ materials, have actually comprised both the ground plane and antenna for broadband, efficient, and conformal antenna demonstrations. These experimental realizations have also shown that the proper selection complex permeability, µ(f) = µ’(f)-jµ”(f), comprising the ground plane plays a key role in RF performance. Larger loss (µ”) is actually shown to improve antenna bandwidth, counter to conventional electrical circuit designs, whereas the magneto-dielectric antenna radiation efficiency is related to the so-called “hesitivity,” [2,3], measured in Ohm/m, which is the peak of the magnetic conductivity spectrum for various magnetic material families. Stated more succinctly, high hesitivity materials where µ”>>µ' (that is, in a traditionally large loss regime) over the targeted frequency band of operation offer a new design paradigm for the most efficient broadband magnetic-circuit antenna.

To make such new antenna designs ubiquitous for DoD applications, improved manufacturing and metrology techniques are required. This includes either new material creation or manufacturing improvements of traditional materials [4]. The two fundamental classes of such materials are ferrimagnetic ceramics (ferrites) and ferromagnetic metals. Challenges for both classes exist in terms of maintaining an effectively high permeability (hesitivity) while creating large area films, laminates, or moldable sheets that also resist degradation due to humidity, corrosion, UV exposure, temperature swings, or similar environmental exposure.

PHASE I: Identify best candidate magnetic film material for synthesis maturation to enable broadband and conformal magnetic-circuit-based antenna demonstration. Produce sample quantities, and verify the sample quality both through material/sample level metrology as well as RF antenna demonstration. Ideally, target such demos across the entire 2 MHz - 3 GHz range, and compare performance to conventional surface-mount antenna designs.

PHASE II: Demonstrate large-area (> 1 m**2), high-tolerance moldable sheets or films of magnetic materials and fabrication metrology. Demonstrate material performance across multiple RF bands via magnetic circuit implementation. Compare performance to both models as well as existing surface-mount antennas. Establish material metrics, validated against antenna demonstration. Project frequency and efficiency metric limits across RF spectrum based upon path to further synthesis and fabrication maturation.

PHASE III DUAL USE APPLICATIONS: Develop data sets for material quality, performance specifications, and expected cost and yield models. Generate samples for fielding in relevant environments (temperature, corrosion, etc.). Study material reliability of conformal antennas for RF sensing, communications, and other DoD applications.

REFERENCES:

1. Smith, M.S., “Properties of dielectrically loaded antennas”, Proc. IEEE, 1977, 124, (10), pp. 837-839.

2. Sebastian, Clavijo, Diaz, Daniel and Auckland, “A new realization of an efficient broadband conformal magnetic current dipole antenna”, IEEE APS-URSI meeting 2013.

3. Diaz, Daniel and Auckland, “A new type of conformal antenna using magnetic flux channels MILCOM Oct 6-8 2014, Baltimore MD.

4. Venkatasetty, Electrodeposition of thin magnetic permalloy films, J. Electrochem. Soc., Vol. 117, No. 3 March 1970, pp. 403- 407.

KEYWORDS: broadband antennas, conformal antennas, high permeability composites, high permeability materials, high permeability thin films, magnetic circuits

AF171-101

TITLE: Additive Manufacturing of Freeform Optical Elements for Imaging System Weight and Volume Reduction

TECHNOLOGY AREA(S): Materials/Processes

OBJECTIVE: Demonstrate the utility (cost, schedule, and performance) of additive manufacturing for large (= 250 mm diameter) freeform optical elements operating in reflection and transmission. Demonstrate weight and volume reductions over current systems.

DESCRIPTION: The field of freeform optics is growing significantly yearly [1] and shows tremendous promise in reducing the mass and volume of attendant optical imaging systems operating at nearly any wavelength. Indeed, such mass and volume reduction can ultimately increase lifecycle sustainability of military electro-optic and infrared (EO/IR) imaging systems by allowing more cooling or other electronics. Further, freeform optical designs may provide for a thermalization of key elements, reduced imaging system integration and assembly costs, and potential for reduced aberrations in imaging over very wide optical bandwidths. Commercially, the field of freeform optics is also receiving attention in reduced size and higher performance mobile imaging applications (cell phones and portable, lightweight cameras), in cinema (both filming and projecting), and in entertainment and gaming (lightweight and rugged virtual reality goggles, for example).

In like fashion, the techniques of additive manufacturing (AM), such as material jetting (including inkjet printing, electro-hydrodynamic jetting, and others), material extrusion, powder bed fusion, and direct energy deposition, among others, are creating an international flurry of interest and burgeoning capability to produce objects not achievable by traditional “subtractive” manufacturing methods [2]. Further, AM offers unique acquisition advantages to military systems that are notoriously small in quantity but high in performance and complexity of integration.

The mating of these two techniques—freeform optics for high-performance, low-mass/low spatial volume, aberration-free imaging systems—and AM for rapid, flexible, and high-performance low-volume-rate production—offer unique capability for emergent imaging concepts and demonstrations. The goal of this topic is for the proposer to demonstrate AM of a large aperture (>=250 mm in diameter) freeform optical imaging system—one transmissive, one reflective. Special attention and consideration will be given to (1) utilizing processes and materials for demonstrations in military relevant wavelength bands, namely short-wave infrared (SWIR, 1.4 µm to 3 µm ), mid-wave infrared (MWIR, 3 µm to 5 µm), and long-wave infrared (LWIR, 8 µm to 14 µm); (2) demos providing imaging system demonstration spanning larger portions of these wavelength bands; (3) proposals developing processes using materials known for favorable environmental robustness (e.g. athermal imaging system designs, materials that are not susceptible to damage from high power incident electromagnetic radiation, and radiation hard and shock and vibration robust materials and processes). Relevant demonstrations may include telescope systems, heads-up display systems, extremely wide-field of view (WFOV) optics, novel and highly accurate beam-steering systems, robust low-light level imaging (for example, hyperspectral imaging with reduced optical scatter), among others.

PHASE I: Identify candidate materials and additive manufacturing (AM) processes to demonstrate military relevant freeform optical imaging elements. Use AM to create and verify the performance of a small-scale (diameter >30 mm) transmitting OR reflecting freeform element. Compare performance to commercial element performing same function. Assess AM production trade-offs (cost, schedule).

PHASE II: Demonstrate large-scale (>= 250 mm diameter) reflective and transmissive freeform optical imaging systems via AM, assess cost, schedule, and performance of low-volume manufacture. Assess imaging quality and ruggedness of such elements, including varying ambient temperature (-50 C)

PHASE III DUAL USE APPLICATIONS: Optimize materials and AM processes to demonstrate freeform elements across wide swaths of SWIR, MWIR, and LWIR bands. Conceive and demonstrate in-line metrology for reduced schedule of manufacture. Project manufacturing costs and schedule for low-rate to larger volume manufacturing runs.

REFERENCES:

1. Rolland, J. and Thompson, K., “Freeform Optics: Evolution? No, revolution!” on the 19 July 2012 SPIE Newsroom (DOI: 10.1117/2.1201207.004309, accessible viahttp://spie.org/newsroom/4309-freeform-optics-evolution-no-revolution? ArticleID=x88361).

2. Diegel, O. et al., “Tools for Sustainable Product Design: Additive Manufacturing,” J. of Sustainable Development, Vol. 3, No. 3, September 2010, pp. 68-75.

KEYWORDS: additive manufacturing (AM), AM, athermal imaging system designs, beam-steering systems, extremely wide field of view (WFOV) optics, WFOV optics, freeform optical imaging, freeform optics, heads-up display systems, hyperspectral imaging, low-light level i

AF171-102

TITLE: Portable, Precision Automated Welding for Aerospace Alloys

TECHNOLOGY AREA(S): Materials/Processes

OBJECTIVE: Develop a portable, automated weld system capable of being taken to a work area to perform automated precision weld repairs on aerospace grade materials.

DESCRIPTION: Performance of structural maintenance and repair on aircraft requires precision welding of advanced aerospace alloys such as Ti 6-4, Ti 6-2-4-2 Si, Al 7075, and Al 6061 on thicknesses up to .25" and lengths up to 6”. Air Force desires a portable automated welding system that can be transported to a work area using normal ground support equipment.

The system must be capable of automatically identifying manually prepared weld location and required weld length and size when queued with rough location data. The data must flow into automated instructions for weldment path and proper weld penetration. Post weld automated inspection must be performed to visual requirements of MIL-STD-2219A Class A to identify completed weld size, shape, and defects. All weld data including post weld inspection, weld settings, process monitoring, and final weld profiles must be captured and stored for use in digital thread. Temperature control of weld and surrounding area required.

Current state-of-the-art (SOA) in the Air Force is manual weld inspection, manual repair and weld preparation, and manual weld and manual weld surface finish. In response to lack of skilled labor and desire for repeatability and precision welding, there is need at depot for automation of some or all of these processes. Industry SOA is weld environment appropriate vision and laser seam finding systems capable of creating 3-D weld profiles of prepped weld joints and automated weld inspection systems capable to detect weld defects down to .005”. Other research programs are addressing the automated NDE and pre weld joint prep and post weld grinding. System flexibility for future capability insertion for automation would include damage NDE, weld prep, post weld finishing and post weld NDE inspection. Current state for automation is increased productivity and repeatability. This program proposes precision welding including penetration and temperature control, integration of vision or laser systems to identify weld joint location, shape and completed weld profiles, and flexibility from automation.

PHASE I: Perform trade studies and research to identify appropriate automation for motion control, precision welding process including penetration control and temperature sensing/control, preweld location and joint configuration mapping and post weld visual inspection scheme, weld monitoring scheme and appropriate sensors, location queuing process, software and hardware requirements including development of graphical user interface (GUI) for operator inputs and system outputs and input requirements for new materials. Identify process to develop location specific weld schedules and parameters necessary to monitor for location specific weld schedule. From results of trade studies and research, provide report identifying preliminary automated weld cell concept and development required to achieve system identified in description.

PHASE II: Design and develop an automated system capable of delivering precision welds and demonstrate on Ti 6-2-4-2 Si plate. When queued with rough location input and start command, automatic detection of weld joint size and location must produce location specific weld parameters for the specified material. Demonstrate GUI for operator inputs, system outputs and system flexibility for addition of materials and future capabilities. Demonstrate temperature control for weld and surrounding weld area. Demonstrate weld monitoring and vision inspection capability. Perform development of location specific weld schedules and demonstrate input capability and flexibility to add new material data. System must be able to control weld parameters in order to achieve precision weld penetration, weld integrity and optionally control temperature limits to protect surrounding materials. From results of Phase II system development, design a portable automated weld cell. Provide analysis of cost, maintenance, and training of the equipment. Provide a list of potential components that could be repaired using this capability.

PHASE III DUAL USE APPLICATIONS: Manufacture and demonstrate a portable, automated weld system capable of precision weld repairs on aerospace grade materials. Demonstrate process of development and input of new material of interest. Demonstrate data capture for digital thread. Prepare a manufacturing plan, bill of materials (BOM0, users' manual and training plan. Develop a test and certification plan and demonstrate on Air Force Depot application of interest. Perform cost analysis and business case for Industry insertion. Perform business case for commercial application and identify key applications areas in the commercial and military markets.

REFERENCES:

1. Department of Defense Standard Practice, MIL-STD-2219 Class B. Retrieved from: everyspec.com/.../download.php?spec=MIL-STD-2219A.010187.PDF.

2. Gas Tungsten Arc Welding. Retrieved from:www.itw-welding.com/media/Pdf/Welding_Support/QSTIGe.pdf.

3. Michael Francoeur, President of Joining Technologies Robotic Industries Association. Gas Tungsten Arc Welding. Retrieved from:http://www.robotics.org/content-detail.cfm/Industrial-Robotics-Industry-Insights/Gas-Tungsten-Arc-Welding/content_id/164.

4. Note: No references for robotic or automated material identification, weld inspection, weld preparation and welding. All technologies exist as individual robotic and automated processes but there is no reference to an integrated system that includes all p

KEYWORDS: gas tungsten arc welding (GTAW), GTAW, robotics, weld and inspection automation, weld inspection, weld repair

AF171-103

TITLE: Tailpipe Coating Thickness Measurement Capability

TECHNOLOGY AREA(S): Air Platform

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.