Scientists have often sought ideas for innovation in the natural world. Using natural substances such as bone for inspiration, researchers from the Massachusetts Institute of Technology have developed a new type of biofilm with the help of bacteria.
Bone is a naturally occurring matrix produced by many organisms by using certain minerals and compounds. Compared to the average synthetic material, living tissues are much more complex and can adapt to changes in its surroundings. Using bacterial cells and a variety of non-biological materials such as quantum dots, nano particles and gold, MIT scientists have succeeded in creating a biofilm that may have a variety of practical applications.
The biofilm produced by the researchers can be used for a variety of purposes such as producing light or conducting electricity. Moreover, this type of biofilm also has one key element that is rarely present in non-organic materials, the ability to respond to stimuli.
"Our idea is to put the living and the nonliving worlds together to make hybrid materials that have living cells in them and are functional," said MIT assistant professor of electrical engineering and biological engineering Timothy Lu. "It's an interesting way of thinking about materials synthesis, which is very different from what people do now, which is usually a top-down approach."
To create the biofilm, the researchers used E. coli, a very common type of bacteria that can be found almost anywhere. Moreover, E. coli also has a very distinct ability that the researchers sought to take advantage of. In order to help E. coli colonies reproduce in certain surfaces, the bacterium naturally produces a type of biofilm using protein. These biofilms are referred to as "curli fibers."
By manipulating the E. coli to produce a variety of curli fibers, the research team was able to create different types of biofilms. One such biofilm contained minute crystals called quantum dots that could have applications in quantum mechanics. Another type of film had tiny gold fibers that could conduct electricity. The researchers published their findings in the online journal Nature Materials.
"It's a really simple system but what happens over time is you get curli that's increasingly labeled by gold particles. It shows that indeed you can make cells that talk to each other and they can change the composition of the material over time," Lu added. "Ultimately, we hope to emulate how natural systems, like bone, form. No one tells bone what to do, but it generates a material in response to environmental signals."
Researchers are hoping that the new biofilm can be used to create more efficient solar panels in the near future. Due to their biological elements, solar panels created from these biofilms may have self-healing properties to repair damage incurred through daily use.
