Engineers Look to Develop Living Infrastructure

A living root bridge in the East Khasi Hills district of Meghalaya, India. Photo courtesy of Getty Images.

A pair of engineering professors at ETH Zürich (Zürich, Switzerland) are spearheading an effort to create self-sustaining, “living” infrastructure that are responsive to their environments and can also monitor their condition and repair themselves as needed.

One potential application of this nascent technology is the use of seeds to “grow” bridges made entirely of organic materials. This science-fiction scenario is the brainchild of Eleni Chatzi, a professor of structural mechanics at ETH Zürich. A civil engineer specializing in structural health monitoring, Chatzi uses a combination of sensors, signal-processing algorithms, and machine learning to diagnose the health of dams, bridges, and wind turbines. 

In order to measure tension, deformation, and other factors, engineers must either install external sensors or incorporate such sensors into the infrastructure design. However, Chatzi says that such practices are both disruptive and expensive. “That’s why we’d like to develop infrastructures and machines with intrinsic intelligence that are aware of their condition even without externally mounted sensors,” she explains.

The concept of “self-aware infrastructure” is not a new one. In recent years, researchers have explored the use of intrinsic self-healing concrete that self-monitors its condition to detect cracks, moisture, or unusually heavy loads, as well as polymers that self-repair when exposed to carbon dioxide in the air. Thanks to breakthroughs in the fields of materials science and biotechnology, scientists are now working to “incorporate biological functions into materials,” says Mark Tibbitt, a professor at the Macromolecular Engineering Laboratory at ETH Zürich.

Tibbitt’s research looks to develop soft, tissue-like polymers for biomedical applications, as well as for home and office use. “The fascinating thing about living organisms is that they perceive their environment, react to it and even heal themselves when injured. We want to instill these qualities in materials and infrastructures,” he says.

Although their research paths are distinct, Chatzi and Tibbitt often discuss their work with one another. They have also engaged materials scientists, chemical, civil and electrical engineers, biologists, and computer scientists about the potential for living, self-​sensing and self-​healing materials and infrastructures.

To that end, an initial workshop and symposium has been planned for spring 2020 in which participants will consider such questions as the safety and stability of living structures and the ways in which humans and animals will interact with engineered environments made of living organisms. “We have to think about bioethical questions and safety concerns from day one,” says Tibbitt.

Source: ETH Zürich, www.ethz.ch/en.html.