FEATURE: Discovery – Research at Princeton

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Children exposed to a lot of sunlight have a higher chance of developing skin cancer as adults, according to the Centers for Disease Control and Prevention. With this in mind, structural designer and assistant professor in the Department of Civil and Environmental Engineering Sigrid Adriaenssens is creating a sun shade designed to account for the sun’s path within a specific geographic location. This would allow the shade to work anywhere, protecting against the sun’s power and helping reduce skin cancer — the most common form of cancer in the United States.

Adriaenssens’ approach is to produce a dome shaped grid for the sun shade that works with surrounding climatic conditions and uses the least amount of building material possible. To do this, her team uses data from the National Oceanic and Atmospheric Administration and NASA coupled with their sun path algorithms to identify specific sunlight angles in the sun shade’s location and ensure that the grid shades for only those angles. This allows the structure to block damaging UV radiation, but lets through light that doesn’t affect the target shade area.

The inspiration for the shade’s design came in part from existing commercial sun shades, which are typically “one design fits all” and thus ineffective at actually shading their target areas. Individuals sitting under a patio set with a sun shade, for example, can find that the perimeter of the table around which they are sitting is not shaded at all, Adriaenssens explained.

Adriaenssens uses a “dialectic” strategy in her work, which is a reference to the dialectic form of discourse that looks for a solution to a problem by using various arguments, or design drivers in this case. For Adriaenssens, the drivers include engineering considerations such as structure and material as well as questions of environmental performance.

“I think sometimes you can design, in a very economic way, very elegant systems,” she said, noting that she encourages the dialectic approach among her students. Adriaenssens’ colleagues, including Assistant Professor of Civil and Environmental Engineering Mark Zondlo, Postdoctoral Research Associate Landolf Rhode- Barbarigos, and graduate students Matthew Horner and Dan Reynolds, recently erected a prototype sun shade near the Princeton University Stadium.

Other sun-related projects that adapt to different environmental conditions are on Adriaenssens’ radar. One of her models takes its cue from plants such as the waterwheel plant (Aldrovanda vesiculosa), which uses two lobes that rapidly snap shut to catch prey. The mechanics of this motion serve as the basis for shading structures that open and close based on the amount of sunlight present at a given time, ensuring lower manufacturing costs and energy consumption.

Adriaenssens hopes that the high efficiency of her creations will ensure a low-resource path to useful designs, especially in cities. With 70 percent of the world population predicted to live in urban environments by 2050, carbon emissions from existing and additional buildings — and the construction materials for creating them — required to support their needs will only increase, she explained.

“We must find more efficient ways to provide people with a good quality of life using fewer resources,” she said. “My research is all about how we can develop an engineering design framework for a future-oriented urban environment.”

By Tara Thean

Image Courtesy Denise Applewhite

Matt Horner and Prof. Adriaenssens, protected from harmful UV radiation under the louvred grid shell prototype.