Professor Michelle Bernhardt-Craig is looking to revolutionise the way we construct objects such as infrastructure or housing. The ambitious plan is to create a sort of high-strength “concrete” out of bacteria and soil. Professor Bernhardt-Craig has been using binder jet 3D printing technology and testing it with various agents and materials. She has, so far, tested the creation of constructs out of gypsum, but is looking into the possibilities presented by regular sand.
In April 2018, Bernhardt-Craig secured a $500,000 grant to grow her research into load-bearing materials. The purpose of the grant was originally to find constructs in nature that can serve as functional building materials. She previously used gypsum to produce a synthetic material that resembles sand, however there was a drawback. As gypsum absorbs moisture and water, the professor is now looking to get a new grant for a 3D printer that is able to process sand.
The project would massively help efforts in areas where concrete can be scarce. Developing a means of printing houses or roads out of sand and soil could be especially useful in outer space or underdeveloped regions here on Earth. It would also be far better for the environment, being naturally occurring and possibly reusable.
MICP and Soil Processing
The picture above shows a gypsum construct she was working on. Working off of this, she wants to create structures that use sand instead. While this version has the material with 3D printed and the gypsum bound with a proprietary glue, Professor Bernhardt-Craig wants to forego the glue entirely, thus opting for soil or microbial induced calcium carbonate precipitation. The bacterial properties make it tougher and more durable overall and the calcium carbonate can create a hardened soil with self-healing fractures in concrete and thus seems ideal. Another possible way to bind the soil is with biopolymers.
Professor Michelle Bernhardt-Craig hopes to partner with a company to take her product to market. The grant project is due to run from July 1, 2018, through June 30, 2023. Currently, the professor is looking to keep on 2 under-grad students as co-researchers. With a project of this much scope and applicability, partnering companies and institutions should be lining up in no time.
Featured image courtesy of University of Arkansas, found through TalkBusiness