EFRI ELiS: Mechanically Adaptive Living Structural Materials

Cornell University, Ithaca NY

Investigators

Abstract

The manufacturing and application of materials used in construction and building materials is energy intensive, generating substantial costs in dollars and carbon emissions. At the same time, building operations themselves are energy intensive, especially when it comes to heating and cooling. In the coming decades, there will be a need for new, more sustainable, and higher-performing building materials. The long-term goal of this project is to establish the technology for building materials that are less energy intensive during manufacturing and also reduce the costs of heating/cooling over the lifetime of the completed building. The specific goal of this project is to enhance the performance of sustainable materials used for insulation by increasing the ability of the material to contribute to the structural demand. In addition to technical achievements, the proposed work includes consideration of the legal challenges associated with the incorporation of such materials into building codes. Additionally, this project establishes a graduate level course for the emerging field of “Engineered Living Materials” that will include cross-campus instruction among the participating universities. Insights from the proposed work will be integrated into educational programs for middle school and high school students from underrepresented groups at each of the participating universities. The proposed research advances technology related to sustainable living building materials by creating materials that adapt to mechanical stresses during use by increasing density and stiffness at regions of greatest mechanical demand. The project focuses on the development of mechanically induced biomineralization in hempcrete, a sustainable building material with negative carbon emissions. The proposed work will advance knowledge in the field of living building materials by establishing the fluid environment necessary for nutrient delivery to resident microbes and the changes in chemical environment associated with ureolytic biomineralization within confined spaces of the living building material. A transformative aspect of the proposed work is the use of mechanically sensitive bacteria that alter the density and stiffness of the building material only at locations of greatest mechanical stress, increasing density and mechanical properties at needed locations while maintaining less dense regions with better insulative capacity This project includes 1) multiscale modeling to determine the transport of nutrients and waste products generated during biomineralization within microscale pores within a living building material, 2) fabrication of test beds of mechanically sensitive organisms using an existing sustainable building material that can benefit from enhanced mechanical performance (hempcrete), and 3) analysis of the legal implications of living building materials, which, unlike other building materials, are purposely designed to change their mechanical performance. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.