A second group of materials includes highly transparent polycarbonate films in the cabin window. These are made of two sheets of Makrofol DE 1-1 polycarbonate film separated by a cushion of air. Other Bayer materials include films for covering structures, wing-covering fabric, and high-performance adhesive and coating materials in the cabin.
"Solar Impulse selected these materials because of their light-weighting capabilities," Rothe wrote. "For example, the polyurethane foam combines design freedom to form the faring and other complex components, as well as high insulation values at a very low density. Polyurethane parts were used where insulation is needed on the plane: cockpit cladding, motor cowling, and wing tips."
The HI-SIB will use the same materials groups: polyurethane foam, polycarbonate, and film and coatings. These will be further optimized, since the second plane needs to be even lighter. The cockpit's insulating foam materials (which also must deliver higher performance) are based on Baytherm Microcell and being co-developed with Solvay. "The material is better due to newly developed formulations, which allow for a significantly lower cell size," Rothe wrote. "These smaller cells make the polyurethane insulation properties even better and the density stays at a very low level. So the total weight should be lower." Another new development is a polyurethane resin for the carbon fiber composite.
For the HI-SIB, Bayer is providing and designing materials and structures. For example, it is handling the design of the cockpit shell. The windshield's sandwich structure will be similar to the HI-SIA's, but Bayer developed a new material that will reduce the likelihood of clouding from water condensation.
The second plane's coatings for all the exterior parts, especially the parts where no solar cells are located, are vital. They are extremely lightweight, allowing optimum protection for the films or textiles underneath. The coatings' "material properties will be the same, but no solvents will be used, which means the material is more ecologically friendly."
Nancy, I had that thought, too, even before I saw the photos. One reason is because of the background info I read for the story of the perpetual-flight plane:
Ann, that was my first thought, when I read the title of your article: that the plane would be built like a glider. Especially with these preliminary designs - that only makes sense...not only for general power consumption given the general inefficiency of solar power, but if there is not enough power, the plane can still safely fly...and land!
AnandY, that type of design detail may be available on the Solar Impulse website. I find it interesting that another solar-powered airplane, the prototype Electric High Altitude Solar-Powered Aircraft (ELHASPA), which we describe here http://www.designnews.com/author.asp?section_id=1386&itc=dn_analysis_element&doc_id=264353&image_number=11 also has very long, thin wings, which are typical of aircraft designed to glide.
Elizabeth, I also was happy to see the lighter alternative materials being used. And I agree that solar power would be ideal for just about everything, if it were feasible in each case. Advances like this one show us that a lot is possible when you combine brains, talent, funding, expertise and willpower.
I really like this idea of a solar plane, thanks for this coverage, Ann. I am impressed at how the use of lighter, advanced materials makes this type of flight possible. Using alternative fuels for airplane travel is really good, but solar power, in my opinion, would be even better.
@Ann, thanks for informative post. Cost of flight reaching all time highs due to a various factors like fossil fuels costs, cuts in government subsidies. There is a need for alternatives energy resource. Solar energy is potential solutions to cut costs.
Artificially created metamaterials are already appearing in niche applications like electronics, communications, and defense, says a new report from Lux Research. How quickly they become mainstream depends on cost-effective manufacturing methods, which will include additive manufacturing.
SpaceX has 3D printed and successfully hot-fired a SuperDraco engine chamber made of Inconel, a high-performance superalloy, using direct metal laser sintering (DMLS). The company's first 3D-printed rocket engine part, a main oxidizer valve body for the Falcon 9 rocket, launched in January and is now qualified on all Falcon 9 flights.
Lawrence Livermore National Laboratory and MIT have 3D-printed a new class of metamaterials that are both exceptionally light and have exceptional strength and stiffness. The new metamaterials maintain a nearly constant stiffness per unit of mass density, over three orders of magnitude.
Smart composites that let the material's structural health be monitored automatically and continuously are getting closer to reality. R&D partners in an EU-sponsored project have demonstrated what they say is the first complete, miniaturized, fiber-optic sensor system entirely embedded inside a fiber-reinforced composite.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.