The dream is that one day we can tune materials as precisely as a piano. Material engineers hope one day to select from a menu of material characteristics at will: hard, sticky, strong, unmeltable, non-toxic, you name it. We’re not there yet. Despite decades of advances, mass manufacturing of custom materials is not as malleable or precise as we might like. That’s changing fast.
One step in that direction was made this year by scientists at Oak Ridge National Laboratory. Publishing in Advanced Materials, the researchers say they have spun out a new class of carbon fibers, exceedingly strong threads engineered at the sub-micron level, suitable for creating almost any strong, lightweight components that would currently be made from plastic.
The raw material? Plastic bags and old carpet. The carbon fiber recipe is a brew of melted polyethylene, which you can get easily from discarded plastic bags or other products. After being re-engineered, the fibers are extruded as microscopic threads in shapes ranging from gear-like cylinders to multifaceted teardrops. Once arranged in mats or bundles, the threads are dunked in acid to set molecular bonds in a permanent state that is resistant to stress and heat.
Oak Ridge is only one effort among many advanced material initiatives springing up around the country. The White House is backing the U.S. Material Genome Initiative (PDF) (we reported on last August), and green chemistry research is appearing in universities and government laboratories.
If many of their ambitious goals are realized, we may see a future of finely tuned custom materials that perform better than anything we have today, without poisoning people or the planet.MJC