Mitigating Fatigue Crack Growth with Engineered Bacteria
Abstract
Damage accumulates in a structure over time as the structure is subjected a series of stressevents. One common mode of damage accumulation, particularly relevant for marine structures,is environmentally assisted fatigue fracture, which results from cyclic mechanical loading withina corrosive environment. Here we propose bacteria-polymer composite-based approaches to firstdetect and then mitigate environmentally accelerated fatigue cracks. Given that the microenvironmentof fatigue cracks depends in part on the material, wewill focus initially on steel as thestructural material. We will use the sporulating bacterium Bacillus subtilis to sense and mitigatecracks. The choice of this bacterium is predicated on its ability to form endospores, ensuringlong-term viability and resilience even in hostile environmental conditions. The spores will bestored within a synthetic polymer coating and activated by either mechanical or chemical stimuli,utilizing distinct approaches for the two stimuli modes, in terms of both polymer matrix designand spore engineering. For crack propagation mitigation, we will investigate chemical passivationapproaches. To our knowledge, there has been noprior work on living material approaches todetect or mitigate damage within steel.Our research objectives are to: (1) engineer detection of fatigue cracks as indicated by substratemechanical deformation; (2) engineer chemical sensing of the crack tip environment during environmentallyaccelerated fatigue crack growth in steel; and (3) investigate approaches to activelymitigate crack propagation. To achieve these objectives, we will utilize synthetic biology inconjunction with continuum mechanics to design and investigate our fatigue crack sensing andmitigation living coating concept. Further, we will use both experimental and computationalapproaches. The proposed work will produce new knowledge in the fields of engineered livingmaterials, continuum fracture mechanics, and syntheticbiology, as well ashave positive impactson the application spaces of ship structural reliability, bioremediation, and food preservation.Our team is well positioned to take on the scientific, technological, and design challenges associatedwith a bacteria-polymer composite-based approach to fatigue crack detection and mitigation.The Giometto lab brings expertise in synthetic biology, biophysics, and biosensor development.The Bouklas lab brings expertise in fracture mechanics, constitutive modeling for engineering materials,and multiphysics modeling. The Silberstein lab brings expertise in polymer synthesis andprocessing, thermo-mechanical characterization of polymers, and polymer constitutive modeling.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 08, 2024
- Source ID
- N000142412479
Entities
People
- Meredith N Silberstein
Organizations
- Cornell University
- Office of Naval Research
- United States Navy