Published on February 8, 2013 by Brenda Mikeo
The question Sigrid Adriaenssens asks is not whether a structure can be built, but rather, if it should be built. As an assistant professor of civil and environmental engineering, a recurring theme in her research and teaching is the search for the optimal form — one that considers elegance, efficiency, and economics in addition to stability and serviceability. She was recently awarded a grant from the Andlinger Center to study elastic structures for energy-efficient architecture with her collaborator, Professor Axel Kilian of the School of Architecture. Adriaenssens spoke with the Center about her research, teaching, and how structures can respond to their environments.
You were recently named a co-recipient of an Andlinger Innovation research award. What is the goal of the project?
Buildings account for about one-third of our total energy usage, and almost 60% of that energy is used for lighting, heating, and cooling. Our project investigates a method of reducing the energy needs of buildings by using bio-adaptive shading modules. These shading devices adjust themselves to the position of the sun and can help make buildings more energy-efficient by providing natural light and reducing the need for artificial heating and cooling. We plan to study elastic structures in plants to see if these mechanisms can translate to energy-efficient architecture.
What inspired you to investigate shading devices that respond to the sun?
A lot of my research looks at adaptive structures — systems that change in response to the environment. For this project I’ll draw inspiration from nature by studying the ways in which plants move. There are plants that move quite a lot: sunflowers move their heads to follow the sun, and plants like the Venus Flytrap make very quick, repetitive movements to catch food. Plant movements are often quite simple in the sense that only one element has to change a little bit to generate an opening and closing mechanism. And that’s what we’re interested in: mechanisms that require very little energy input to generate movement.
Is there a lot of contemporary research on this topic?
No, not very much because the concept is new. In my field we’re traditionally taught that structures should not move, that they should stay put. We’re taught that too much elastic deformation is considered a failure of design. This new approach requires changing our assumptions about what constitutes good building design.
What are some other ways civil engineering can address environmental issues?
There is a lot of research being done at the materials science level, like making concrete more green and finding bio-composites. In my department there are people studying the effects of erosion, wind flow, pollution flow, and climate change. I think all these topics are interesting, but we also need to look at building design in a more comprehensive way. Engineers have to work together with architects and planners to consider the larger issues. At the moment these elements are being studied separately.
It’s also important to look at how structures can be resilient and bounce back in response to adverse climate conditions. As more people live in urban areas, more people will be affected by the way structures respond to natural disasters.
You were advisor to Mariam Wahed ’14 for her summer 2012 Andlinger Center internship. How did you collaborate with her on her project?
Mariam studied a traditional roof type that has been around since the Industrial Revolution, but isn’t used much anymore. When the first industrial factories were built, there was no artificial light, so they had to bring in as much natural light as possible. Not a lot of thought went into energy efficiency, but they found that curved roofs with north-light configurations optimized the natural light inside the buildings. We wanted to find out why this design isn’t used much anymore and if there is a good reason to resurrect it. It turns out that in warm geographic zones this type of roof can be very efficient. For multinational companies that manufacture goods all over the world, this type of curved roof system could significantly reduce energy consumption.
What do you like most about teaching at Princeton?
One of the best things about working with Princeton students is that they are so full of ideas; they want to change the world. Their optimism and enthusiasm for the future is refreshing — it’s really an incredible gift. It energizes me in my own work.
What do you hope to inspire in your students?
I want them to learn that they shouldn’t feel intimidated because they don’t know everything yet. I’m here to give them the tools and show them how to realize their ideas. If they are eager to learn and they work hard, they can get great results. Not knowing all the steps in advance shouldn’t stop them from pursuing their ideas.