Engineered Biological Cement for Surface Hardening in Semi-Aquatic Environments

BioSqueeze, Inc. (BSI) proposes using microbially induced calcium carbonate precipitation (MICP) to meet DARPA’s SBIR program objective of “pushing the utility of biological cement derived from living organisms to produce hardened surfaces in semi-aquatic environments.” Our MICP technology will reduce the effects of beach erosion and greatly improve the ability of vehicles to transition from marine to terrestrial environments. When commercialization is achieved the BioSqueeze® MICP process can be leveraged to create innovative new solutions in the road and foundation construction industry along with new capabilities for the military.  Our proposal, entitled “Engineered Biological Cement for Surface Hardening in Semi-Aquatic Environments,” is well positioned to meet this program objective. This proposed 24-month (R&D) program builds on the existing strengths and capabilities of BSI, in collaboration with the Center for Biofilm Engineering at Montana State University (MSU). Select microbes contain an enzyme that promotes hydrolysis of urea (ureolysis). This triggers an increase in pH and carbonate concentrations that, in turn, can cause dissolved minerals to precipitate and form calcium carbonate solids similar to limestone. Partially filling the void spaces in sand with calcium carbonate greatly increases the strength of the sand matrix thereby increasing bearing capacity, reducing erosion potential, and simultaneously allowing drainage to proceed. Given our recent success commercializing MICP technology in the oil industry for sealing wellbore leakage, we are now expanding the application of our proprietary technology to address surface hardening-related applications in semi-aquatic environments and other soil/sand stabilization applications. Over the past decade we have completed numerous projects demonstrating the ability of our BioSqueeze MICP process to decrease permeability and increase material strength. Under this 24-month SBIR project we will develop and demonstrate technology and methods for MICP injection into saturated sand to achieve a desired increase in bearing capacity as related to density, stiffness, compressive strength, and California Bearing Ratio. For the Month 9 and Month 18 Readiness Tests, BSI will perform MICP testing on progressively larger and more complex test beds. MSU will investigate geotechnical properties of the biomineralized sand. The Month 24 Ultimate Challenge will consist of biomineralizing an actual beach using the optimized parameters obtained during the prior Readiness Tests. The end goal after 24 months will be to have demonstrated our application in surface hardening for amphibious landing.