Understanding the physical mechanisms of biomineralization and the development of force microscopy-based methods of investigating mineralization at the nanoscale
Contact: Chris Orme
Studies the fundamental physics of crystallization and materials assembly with application to biomineralization, biomimetic synthesis, controlled synthesis of nanostructures, catalysis, interfacial dynamics, and electrochemical deposition.
The atomic force microscope (AFM) has been used since 1986 to produce topographic maps of nanostructures. An ultrasharp tip scans across a sample’s surface, and a computer records the path of the tip, slowly building a three-dimensional image. When force and displacement data are combined in various algorithms, the resulting calculations reveal information on mechanical properties, such as hardness, and any other reactions to an applied force.
Unlike the scanning electron microscope, which provides a two-dimensional image of a sample, the AFM provides a true three dimensional surface profile. Additionally, samples viewed by AFM do not require special treatment that would destroy the sample. AFMs also do not need to operate in a vacuum environment, as do electron microscopes. The AFM can be used on materials that don’t conduct electricity. The microscope is unique in its ability to measure the mechanical properties of both hard and soft materials. The latter has traditionally been more difficult because soft materials, such as biological tissues, are part solid and part fluid.
Although the AFM produces a smaller image area than electron microscopes (micrometers versus millimeters, respectively), it can image and manipulate matter at the nanoscale, allowing researchers to both study a molecule’s structure and properties and organize molecules into predetermined patterns.