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RICE UNIVERSITY engineers are using 3-D printers to turn structures that have until now existed primarily in theory into strong, light and durable materials with complex, repeating patterns. The porous structures called schwarzites are designed with computer algorithms, but Rice researchers found they could send data from the programs to printers and make macroscale polymer models for testing. Their samples strive to use as little material as possible and still
provide strength and compressibility. It may someday be possible, researchers said, to print an entire building as one schwarzite “brick.” Schwarzites, named after German scientist Hermann Schwarz, who hypothesized the structures in the 1880s, are mathematical marvels that have inspired a large number of organic and inorganic constructs and materials. Such structures remained theoretical until 3-D printers provided the first practical way to make them. The Rice lab of materials scientist Pulickel Ajayan, in collaboration with researchers at the
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University of Campinas, São Paulo, investigated the bottom-up construction of schwarzites through molecular dynamics simulations and then printed those simulations in the shapes of polymer cubes. “The geometries of these are really complex; everything is curved, the internal surfaces have negative curvature and the morphologies are very interesting,” said Rice postdoctoral researcher Chandra Sekhar Tiwary, who led an earlier study that showed how seashells protect soft bodies from extreme pressure by transferring stress throughout their structures. “Schwarzite structures are very much the same,” he said. “The theory shows that at the atomic scale, these materials can be very strong. It turns out that making the geometry bigger with polymer gives us a material with a high load-bearing capacity.” “It is a little surprising that some atomic-scale features are preserved in the printed structures,” said Douglas Galvão, a professor at the University of Campinas who studies nanostructures through molecular dynamics simulations. He suggested the project when Tiwary visited the Brazil campus as a research fellow. “After some tentatives, it worked quite well. This paper is a good example of an effective theory-experiment collaboration.” In the far future, the researchers envision printing 3-D schwarzites with ceramic and metallic materials on a grander scale. — MIKE WILLIAMS
G LO BAL H E ALT H
MacArthur Foundation Gives $15 Million for NEST360° NEST360°, an international team of engineers, doctors and global health experts, has won $15 million through the MacArthur Foundation’s inaugural 100&Change competition. Four finalists from a field of more than 1,900 applicants vied for a $100 million top prize, which was announced Dec. 20, 2017, by the foundation. “Our whole team is committed to continuing our work to scale NEST (Newborn Essential Solutions and Technologies) across Africa in order to save 500,000 newborn lives every year,” said Rice bioengineering professor and NEST co-founder Rebecca Richards-Kortum. NEST partners include Rice 360° Institute for Global Health, the University of Malawi, Northwestern University, the London School of Hygiene & Tropical Medicine and 3rd Stone Design of San Rafael, Calif. “We’re doubly grateful to the MacArthur Foundation, both for its $15 million commitment and its confidence in making us a 100&Change finalist,” said RichardsKortum, director of the Rice 360° Institute for Global Health. More than 1 million African newborns die each year, and most could be saved with simple technologies that keep babies warm, help them breathe, and help doctors diagnose and manage infections. NEST360° is creating a rugged package of 17 Newborn Essential Solutions and Technologies for African hospitals, as well as the distribution network to affordably deliver and repair them continentwide. Twelve of the 17 NEST technologies have already been created or are in clinical testing, and prototypes exist for five more. Several NEST devices were invented by Rice students at the university’s Oshman Engineering Design Kitchen and were improved and tested by Rice 360° students and staffers in Houston and Blantyre, Malawi. — JADE BOYD
S C H WA R Z I T E P H OTO BY J E F F F I T LO W N E ST 3 6 0 º P H OTO BY B R A N D O N M A RT I N
Researchers use 3-D printers to turn century-old theory into complex schwarzites.