Researchers at Purdue University (West Lafayette, Indiana, USA) have concocted a 3D-printed cement paste modeled after the tough outer shells of arthropods such as inspects, spiders, and crustaceans. Just as arthropod shells adapt to external pressure by strengthening as cracks try to twist, the Purdue researchers believe that their 3D-printed cement paste can aid in the construction of more resilient structures able to weather the effects of natural disasters.
The inspiration for this arthropodal design came from earlier research by members of the Purdue research team in which they identified the mantis shrimp as a basis for creating new composite materials. Pablo Zavattieri, Purdue professor of civil engineering, was among the researchers who noted that the mantis shrimp has a “dactyl club” appendage it uses to subdue prey and that grows tougher on impact through twisting cracks. “The exoskeletons of arthropods have crack propagation and toughening mechanisms that we can reproduce in 3D-printed cement paste,” Zavattieri said.
Purdue engineers are the first to use 3D printing technology to create bioinspired structures to create cement-based materials. In addition, they relied on micro-CT scans to analyze the 3D-printed cement paste, particularly how certain weak characteristics may promote cracking. According to Mohamadreza "Reza" Moini, a Purdue Ph.D. candidate of civil engineering, “3D printing cement-based materials provides control over their structure, which can lead to the creation of more damage and flaw-tolerant structural elements like beams or columns.”
The team experimented with various 3D-printing techniques, or “architectures,” that would allow for new behaviors once the cement hardened. From these experiments, they hope to determine which 3D-printed architecture might result in the most resilient structures. This work was funded by the National Science Foundation and supported by the 2017 Major Multi-User Equipment Program at Purdue.
Source: Purdue University, www.purdue.edu/newsroom