A new biobridge located in the city of Eindhoven will build on the Netherlands’ reputation when it officially opens to the public on Thursday. The 46-foot long footbridge is not only constructed out of sustainable hemp and flax fibers, but it is also crammed with 28 embedded sensors, which will measure its durability over time.
“Because the materials we are using have not regularly been used for this application before, the sensors are there to monitor how the bridge holds up over time,” project leader Rijk Blok, a professor of Structural Design at Eindhoven University of Technology, told Digital Trends. “The sensors are extremely thin and constructed from glass fiber, positioned at regular intervals across the bridge. Inside each one is a very small hologram which, if you pass a light through it, will let you measure strain at that specific point through shifts in the light spectrum.”
At first, reading these sensors requires a person to physically visit the site to do this light-based measurement. However, Blok said he hopes this will soon change. “In time, it’s our goal to attach this bridge to the Internet of Things, which will let us monitor it even more precisely,” he said.
Beyond the sensors, the most notable aspect of the bridge is the sustainable materials it is constructed from. The hemp and flax materials are held together using a polylactic acid foam core, which ultimately creates a solid bioresin that is greener than conventional resins. When the bridge is nearing the end of its lifespan — which Blok said should be on a similar timeline to a bridge constructed out of wood — the bioresin can be composted or recycled.
“These materials are already used in smaller creations, such as hockey sticks, but we wanted to see if it was possible to make a whole structural application using them,” Blok said. ‘The building industry is responsible for a lot of material waste. We wanted instead to embrace sustainability.”
At present, the fact that bioresins are produced in small quantities means they are not price-competitive with other, less eco-friendly materials. However, Blok noted that this will change as more and more producers take up the green mantle.
“I see this project as proof positive that these kinds of materials can be used in structural applications,” he said. “It means that if we want to reduce waste in buildings — particularly when you’re dealing with structures that have a shorter service life and need to be changed often — these kinds of materials are ideal.”