OBJECTIVE: To develop laser nanostructuring technologies for durable, anti-corrosive, self-cleaning, hydrophobic surfaces.
 

DESCRIPTION: Under a prior Army R&D effort, the Army observed promising results using laser nanostructures to create super black surfaces. This effort will explore novel methods that leverage this technology to create durable, low-cost nanostructured surfaces for armament applications. In particular, this SBIR topic seeks to explore novel means of employing lasers to treat large areas and large volumes of material in a cost-effective manner. The primary properties of interest include super-hydrophobic, anti-corrosive, and self-cleaning metal surfaces. The topic also solicits low-cost, high-volume methods for using this technology to impart anti-reflective, self-cleaning surfaces to transparent glass. A successful proposal will address how to optimize the longevity of the treated surface for rugged environments. Solutions that involve the deposition of another material on the substrate should avoid hazardous materials and processes.The effort should also address laser treatment methods for difficult geometries, e.g., a gun bore.
 

PHASE I: Using the proposed methods, treat five G43400 (4340) steel test panels for each manufacturing concept under consideration. Document the contact angle and the sliding angle achieved and demonstrate the self-cleaning property. Evaluate the treated samples using standardized ASTM salt fog corrosion testing, hardness and abrasion tests. Demonstrate the proposed concept for treating glass on a curved glass surface. Treat four 75mm diameter plano-convex lenses (focal length of 150mm or less) for each manufacturing concept under consideration. Document the hydrophobicity, reflectivity/transmissivity, and abrasion resistance of the surface. Document aberations induced by the process, to include both traditional optical aberrations and hazing effects. Provide a detailed scale up plan, including cost analysis, for large-scale, low-cost (no more than 20 percent of the treated material cost) production. Incorporate a design for a prototype process to treat large surface areas.
 

PHASE II: Optimize the treatment methodologies proposed in phase I for glass, with a focus on high-volume treatment (volume defined as ~10,000 units per month). Address any technical deficiencies identified in Phase I (i.e. abrasion issues, hazing). Demonstrate the proposed concept for treating other steel and engineering alloys, including UNS G10100 (1010) steel, S17400 (17-4 PH) steel, UNS A97075 (7075) Al, and UNS R56401 (Ti 6Al-4V) Ti. Address any technical deficiencies identified in Phase I (i.e. corrosion issues, hardness issues, abrasion issues). Demonstrate the ability to uniformly treat 3'x 3' metal and glass surface area at a rate of three units per hour. Demonstrate the ability to treat the interior geometry of smooth and angular 0.30"x20" G43400 (4340) steel alloy tube in a repeatable fashion at a rate of at least 12 per hour.
 

PHASE III DUAL USE APPLICATIONS: Provide small arms demonstration articles to evaluate improvements to reliability, maintainability, and system longevity. License or subcontract treatment process to prime DoD contractors producing armaments, marine articles, vehicles, aircraft, CBRNE equipment, textiles, and medical devices.
 

REFERENCES:

1. Kuang, Zheng, Walter Perrie, Jonathan Leach, Martin Sharp, Stuart P. Edwardson, Miles Padgett, Geoff Dearden, and Ken G. Watkins. "High throughput diffractive multi-beam femtosecond laser processing using a spatial light modulator." Applied Surface Science 255, no. 5 (2008): 2284-2289.
 

2. Park, Kyoo-Chul, Hyungryul J. Choi, Chih-Hao Chang, Robert E. Cohen, Gareth H. Mckinley, and George Barbastathis. "Nanotextured Silica Surfaces with Robust Superhydrophobicity and Omnidirectional Broadband Supertransmissivity." ACS Nano: 3789-799.
 

3. Vorobyev, A. Y., and Chunlei Guo. "Multifunctional Surfaces Produced by Femtosecond Laser Pulses." Journal of Applied Physics, 2015, 033103.
 

4. Tang, Ming-Kai, Xing-Jiu Huang, Zheng Guo, Jin-Gui Yu, Xue-Wu Li, and Qiao-Xin Zhang. "Fabrication of robust and stable superhydrophobic surface by a convenient, low-cost and efficient laser marking approach." Colloids and Surfaces A: Physicochemical and Engineering Aspects 484 (2015): 449-456.