From Marble Decay to Living Concrete: KNI Lab Engineers Self-Healing Materials

The Kingsman National Institute (KNI) today announces a major new cross-faculty initiative from our Hellenic Centre for Sustainable Engineering (HCSE) and the School of Life Sciences & Biotechnology. This research, which moves to the very heart of our “Athenian Synthesis” philosophy, is not a simple improvement on existing building materials; it is an effort to create an entirely new class of “Engineered Living Materials” (ELMs).

The goal is to develop a carbon-negative “living concrete” that can autonomously self-heal, a direct response to two existential crises: the profound carbon footprint of the modern construction industry and the constant, costly battle to preserve our physical heritage.

For us at KNI, this challenge is not abstract. Here in Athens, we are the daily custodians of a 2,500-year-old architectural legacy. We watch as the marble of the Acropolis and other classical monuments is relentlessly eroded by environmental stress and material decay. Simultaneously, the 21st-century solution to construction—Portland cement—is responsible for a significant percentage of global carbon emissions.

Our current materials are failing both our future and our past. This new initiative is our proposed solution.

The project is a mandatory and deeply integrated collaboration between two of our leading faculties, embodying the kind of “imperfect” but necessary synthesis we value.

1. The Engineering (HCSE): The team led by Professor Kaarina Rantanen is developing the material “scaffold.” This is the structural, non-living component—a new, low-carbon concrete mixture that is engineered to be highly porous at a microscopic level. The challenge here is a fundamental trade-off: the material must be porous enough to house a living colony, yet structurally sound enough to serve as a load-bearing construction material.
2. The Biology (Life Sciences): The team led by Dr. Isabella Rosetti is engineering the “living” component. Her lab is specializing in non-pathogenic, spore-forming bacteria, such as Bacillus pasteurii. These bacteria are introduced into the liquid concrete mix. As the material cures, the bacteria become dormant, suspended in the porous matrix for decades.

The innovation lies in the activation of the material. When a micro-fracture forms—a common, inevitable result of stress, weathering, or seismic activity—it cracks open the tiny pores. Air and moisture enter, which serves as the “trigger.” This “wakes up” the dormant bacteria.

In their awakened state, the bacteria begin to metabolize, and their biological by-product is calcium carbonate (calcite)—in essence, they precipitate new, rock-hard minerals. They literally “heal” the crack from the inside out, sealing the damage before it can spread and restoring the material’s structural integrity. Once the crack is sealed, the air and moisture are cut off, and the bacteria go dormant once more, ready for the next call to action.

This process is not theoretical; it is a functioning, though still imperfect, reality within our laboratories. The current friction in the project is not if it works, but how to optimize it.

Professor Rantanen’s team is grappling with the fact that the bio-concrete, while resilient, does not yet possess the same compressive strength as traditional, steel-reinforced concrete. Dr. Rosetti’s team is working to “tune” the bacteria to ensure a 50-year-plus dormancy and to maximize the healing speed. This has led to a core philosophical debate within the team: Do we accept a 10% reduction in initial strength in exchange for a 500% increase in the material’s lifespan and a zero-maintenance profile?

This is the Athenian Synthesis in its purest form. We are using the most advanced tools of 21st-century biotechnology and genetic engineering to solve a materials problem as old as the Parthenon’s first iron clamps. The project, which will inform new modules for both our BEng and BSc students, aims to create a new philosophy of construction—moving away from static, “dead” materials that decay, and towards dynamic, “living” systems that endure.

The goal of the Kingsman National Institute is not only to study our heritage, but to create the technologies that allow our own 21st-century contributions to last just as long.