Made of Sterner Stuff
Orthopedic materials are challenged to migrate away from
metal while retaining metallic strength.
Sam Brusco • Associate Editor
Graphene—the two-dimensional allotrope of carbon tak- ing the form of a two-dimensional, atomic scale hexago- nal lattice in which one atom forms each vertex—was
discovered by University of Manchester scientists in 2004. Or,
rather, one should say it was rediscovered, as it had unintentionally been produced in small amounts with pencils or other graphite uses for centuries. The University of Manchester researchers
were the first to create and document graphene flakes one atom
thick, and because of this, graphene was awarded its 2D status.
Two hundred times stronger than steel, immensely light, and an
excellent conductor, it is being hailed as the next “wonder material” for biomedical applications. And once manufacturers can
discover a method to produce it beyond haphazard flakes, graphene could usher in new classes of orthopedic technologies.
For example, in September 2016, the Rice University lab of
materials scientist Pulickel Ajayan, in concert with colleagues in
Texas, Brazil, and India, were able to weld flakes of graphene ox-
ide in porous solids using spark plasma sintering. The researchers
discovered the 3D graphene material compared favorably with
titanium—a standard bone-replacement material—in both me-
chanical properties and biocompatibility.
“We started thinking about this for bone implants because
graphene is one of the most intriguing materials with many
possibilities and it’s generally biocompatible,” commented Rice
postdoctoral research associate Chandra Sekhar Tiwary, co-lead
author of the paper on the discovery in Advanced Materials, with
Dibyendu Chakravarty of the International Advanced Research
Center for Powder Metallurgy and New Materials in Hyderabad,
India.“Four things are important: its mechanical properties, density, porosity, and biocompatibility.”
Anchor system manufactured using VESTAKEEP PEEK. Image courtesy of Evonik Corporation