University of Newcastle building scientists have developed a means of repairing damaged or deteriorated concrete using a genetically engineered strain of a common soil bacteria. Nicknamed "BacillaFilla," the bacteria have been modified so that they migrate into the deepest parts of cracks where they then begin to produce calcium carbonate. Calcium carbonate binds with concrete and can repair small fractures and restore broken concrete to its original strength.

This is not unlike an earlier EcoGeek story about bendable, self-healing concrete which also uses calcium carbonate to heal small cracks in concrete. But where that method called for the introduction of the calcium carbonate into the concrete when it was produced. The bacterial method allows the same process to be applied to old concrete that was not made with calcium carbonate.

A number of safeguards have been incorporated into the bacteria to ensure that they work only where it is wanted. The researchers have tweaked its genetic properties such that it only begins to germinate when it comes in contact with the highly-specific pH of concrete. Once the cells germinate, they are programmed to crawl as deep as they can into cracks in the concrete, where quorum sensing lets them know when enough bacteria have accumulated. This enables the bacteria to target the weak points of damaged concrete and to work in a useful and organized fashion only where the repair is needed. In addition, the bacteria also contains a self-destruct gene, so that it will not propogate beyond where it is intended to go.

As we noted earlier, "[Concrete] is not the most beloved green building material, [but] it has properties that make it eminently useful for engineers and architects for a number of purposes. Given that there is not going to be a sudden moratorium on using the stuff, it's better to have improvements that can keep from having it go from useful building material to landfill."

image: CC 2.0 by ShaireProductions

via: Archinect and BoingBoing

We are always intrigued by biomimetic technologies that find answers based in imitating naturally developed systems. Mechanical locomotion that imitates animal locomotion is particularly interesting. So we liked finding this video of a robotic snake being which is developed by a team at Carnegie Mellon University.

The motion of the snake-bot would allow it to maneuver through tighter spaces than either people or other mechanisms can easily move through. According to the researchers, "Snake robots can use their many internal degrees of freedom to thread through tightly packed volumes accessing locations that people and machinery otherwise cannot use." The flexibility and maneuverability of the snakebot allow it to move through a wide range of terrain types, and could be useful for a range of tasks from building maintenance to field research.

See the video after the jump...