Researchers from the University of Glasgow and the University of Sydney have developed an approach that enables 3D-printed materials to detect and map damage as it develops, potentially supporting future applications in structural health monitoring.
The international research team incorporated carbon nanotubes into 3D-printed plastic lattice structures, allowing electrical currents to pass through the materials. By measuring changes in electrical conductivity as the structures were subjected to increasing loads, the researchers used electrical impedance tomography (EIT) to create real-time maps of changes occurring within the material.
EIT is commonly used in medical settings to monitor lung function. The technique uses electrodes to measure how electricity moves through a material and can reconstruct images of changes occurring internally without invasive procedures.
According to the University of Glasgow, the researchers adapted the technique to monitor the structural health of architected metamaterials, which use carefully designed arrangements of struts and spaces to achieve properties such as low weight, strength, impact resistance or flexibility.
The team tested rectangular lattice structures measuring 48 millimetres across, stretching them until they failed while monitoring changes in their electrical behaviour. As the structures deformed, changes in their conductive pathways affected the voltage measurements collected by external electrodes.
A computer algorithm then translated those measurements into maps showing where electrical properties were changing and how damage was progressing. The researchers reported that the system could identify damage occurring away from the electrodes and localise it to approximately one strut from its actual position.
The researchers also introduced small cracks into some of the lattice struts and found that the system could track the cracks as they spread under increasing strain. Results were compared with direct observations of the structures to validate the damage locations and eventual failure points.
Professor Shanmugam Kumar of the University of Glasgow’s James Watt School of Engineering said the approach provides a more detailed view of structural behaviour than conventional measurements.
“Conventional measurements can tell us what is happening at a particular location in a material, or provide an overall, averaged indication of the structural health of the whole structure,” Kumar said. “However, they cannot show us in detail where damage is developing and how it is spreading throughout the structure.”
Kumar said the combination of lattice structures and EIT could provide a basis for detecting damage before failure, while noting that additional development is required.
“This technique could open up potential applications in areas such as structural health monitoring and other advanced engineering systems, although further work is needed to develop and scale the technology for practical applications,” he said.
The University of Glasgow said the research builds on previous work by its Sustainable Multifunctional Materials and Additive Manufacturing Lab, including modelling work published in 2024 examining changes in the electrical conductivity of lattice materials under strain.
The researchers said the technology could eventually have applications in areas including medical implants, aircraft components and vehicle structures, where monitoring how materials respond to ageing or impacts could provide additional information about structural condition.
The research, led by academics from the UK and Australia, was published as an Early View paper in Advanced Functional Materials under the title Full-Field Damage Monitoring in Architected Lattices Using In situ Electrical Impedance Tomography. The work was supported by University of Sydney–University of Glasgow Ignition Grants and a Vaibhav Fellowship awarded to Kumar.
