IISc team’s bacteria-based method mayhelp repair cracked bricks on Moon

 

 

 

RESEARCHERS have developed amethodusingbacteriatorepair bricks used to build structures on the Moon that can develop cracks due to the widely swinging temperatures on the lunar surface. A teamofresearchers from the Indian Institute of Science (IISc), Bengaluru said future explorations of the Moon are no longer planned as “flyby” missions, instead involve setting up a permanent habitat -- for example, NASA’s Artemis missions. However, the lunar environment is extremely harsh. Temperatures can swing from 121 degrees Celsius to -133 degrees Celsius in a single day and the Moon is also constantly hit by solar winds and meteorites, they said.

 

Bricksexposedtosuchanenvironment can develop cracks, whichcanweakenthestructures built using them, the team said. Ina researchpaper, published in the journal Frontiers in Space Technologies, the authors describedthatdefectswere artificially created in bricks, into which a slurry made of ‘Sporosarcina pasteurii’ bacteria, guar gum and a lunar soillike material was poured. The bacteria can decompose urea in the environment to convertitintocarbonateandammonia. Calcium in the bricks can reactwithcarbonate to form calcium carbonate -- which along with guar gum serves as “both a filler and a cementing agent”, thereby repairing the cracks, the authors said. They also found that the reinforced bricks were able to withstandtemperaturesrangingfrom 100 degrees Celsius to 175 degrees Celsius.

 

“Temperature changes canbe much more dramatic on thelunar surface, which can, over aperiodoftime, haveasignificanteffect,” co-author KoushikViswanathan, associate professoratthedepartmentofmechanical engineering, IISc. Lead author Aloke Kumar, associateprofessoratthedepartmentofmechanicalengineering, IISc, said, “We were initially not sure if the bacteria would bindto the sintered brick. But wefound that the bacteria can not only solidify the slurry but alsoadhere well to this other mass.”Sinteringistheprocessofheating a compact mixture of soillikematerialandapolymercalled‘polyvinyl alcohol’ to very hightemperatures for creating muchstronger bricks. “It’s one of the classical waysofmakingbricks. It makesbricksof very high strength, more thanadequate even forregular housing,” Kumar said.