Electrochromic Visors for Advanced Spacesuit Helmets

NASA's Extravehicular Mobility Unit (EMU) is a personal spacecraft that comprises the spacesuit assembly and life support systems. The current EMU has a manually operated extravehicular visor assembly (EVVA) that uses a reflective gold visor to reduce the intensity of incoming solar radiation. This binary method requires crew members to manually raise or lower the visor depending on ambient light conditions. There is a need for developing an advanced visor system with tunable tinting to provide improved visibility with hands free operation. Integration of a dynamically switching technology with NASA�s next generation spacesuit helmet would provide continuous shading, radiation protection, and optimized light modulation.

Taking advantage of solution processed electrochromic polymers (ECP), Giner is developing a functionally improved alternative to the existing EVVA. Giner�s automated polymer processing on doubly-curved surfaces and electrochromic device fabrication methods are readily adapted to a wide variety of substrates with unique geometries. By combining color-neutral ECPs with transparent electrode coatings, Giner has successfully demonstrated tunable optical switching on curved polycarbonate substrates and obtained high optical contrast (>55% ?T at 550 nm) with rapid response times (<3 sec). The devices show excellent switching stability (<5% ?T loss over 1,000 switches), long optical memory (<1% ?T loss after removal of power at open circuit), and low energy consumption (0.150 watt-Hours per 1,000 cycles for 6� x 10� active area). Fully developed, Giner�s dynamic visor will be compatible for integration with NASA�s new generation spacesuit helmet to allow instant darkening when exposed to sunlight to protect the astronaut�s eyes from solar glare. In addition, the versatile and scalable device platform could provide variable shading on windows used in space stations and vehicles, or on deep space shelters.