Living Materials': Inspired By Bone, MIT Invents E. Coli-Based Substance That Grows Itself
Someday batteries, solar panels, and even medical devices could be made from so-called "living materials." In a new experiment, the Massachusetts Institute of Technology says it combined the cells of the bacterium E. coli with bits of gold and quantum particles to form a new kind of material that conducts electricity and could one day heal itself and adapt to its environment.
Like Us on Facebook
"Living materials can grow, move, learn, and self-organize," according to Harvard's Wyss Institute, which conducts living materials research. "They are responsive, adaptive, programmable, and self-healing; they can be stronger than steel, and better 'engineered' than a suspension bridge." Scientists have long recognized the potential to harness living cells for human-scale purposes, from robotics to home construction, and they're just beginning to work out the specifics.
In the new study, published Sunday in Nature Materials, a team of MIT and Harvard scientists explain how they caused bacteria to latch onto chains of nonliving particles. E. coli is notable because it has parts called "curli fibers" that help each bacterium grab onto surfaces. Scientists can affix proteins called peptides to those curli fibers. The peptides, in turn, are capable of snagging nonliving pieces, such as the gold nanoparticles, and integrating them into the organic material. In this way, scientists infused a metal capable of conducting electricity with a living E. coli cell.
After that, they engineered the cell to respond to commands by genetically disabling its natural ability to produce curli fibers and replacing it with an order to produce curli fibers only when certain kinds of molecules were present. When scientists added the molecules and some gold nanoparticles, the bacteria responded on cue: it grew curli fibers and attached the gold, self-assembling into a conductive chain.
The goal is to one day create materials that assemble without human input. "Ultimately, we hope to emulate how natural systems, like bone, form," Timothy Lu, senior author of the paper, tells MIT News. "No one tells bone what to do, but it generates a material in response to environmental signals."
© 2012 iScience Times All rights reserved. Do not reproduce without permission.