They were surprised by the chemical heterogeneity of the fibers, which hints at how organisms modulate chemistry at the nanoscale. Joester and Gordon are anxious to learn more about how the organic fibers interface with the inorganic minerals, which is key to understanding hybrid materials.
"The tooth's toughness comes from this mix of organic and inorganic materials and the interfaces between them," Joester said. "While this is in principle well known, it is intriguing to think we may have overlooked how subtle changes in the chemical makeup of nanoscale interfaces may play a role in, for instance, bone formation or the diffusion of fluoride into tooth enamel. In this regard, atom-probe tomography has the potential to revolutionize our understanding."
Atom-probe tomography (APT) produces an atom-by-atom, 3-D reconstruction of a sample with sub-nanometer resolution. But many in the field didn't think APT would work to analyze a material made up of organic and inorganic parts.
Fortunately for Joester and Gordon, Northwestern has both David Seidman, a leader in the field who uses APT to study metals, and two of the few APT instruments in the country. (There are less than a dozen.) Seidman, Walter P. Murphy Professor of Materials Science and Engineering, encouraged Joester to take the risk and use APT to study biological architectures. The scientists also were able to exchange ideas with the engineers developing 3-D atom-probe instruments at CAMECA, a scientific instrumentat
|Contact: Megan Fellman|