AVS 52nd International Symposium
    Nanometer-Scale Science and Technology Wednesday Sessions
       Session NS-WeM

Paper NS-WeM3
Bioelectromechanical Imaging by Scanning Probe Microscopy: Galvani's Experiment on the Nanoscale

Wednesday, November 2, 2005, 9:00 am, Room 210

Session: Nanometer Scale Imaging
Presenter: S.V. Kalinin, Oak Ridge National Laboratory
Authors: S.V. Kalinin, Oak Ridge National Laboratory
B.J. Rodriguez, North Carolina State University
S. Jesse, Oak Ridge National Laboratory
A.P. Baddorf, Oak Ridge National Laboratory
A. Gruverman, North Carolina State University
Correspondent: Click to Email
Coupling between electrical and mechanical behavior is a universal feature of biological systems. However, macroscopic studies are inherently limited by the complex structure of these materials. Here, we demonstrate a scanning probe microscopy (SPM) based approach for electromechanical imaging and spectroscopy of biological systems based on Piezoresponse Force Microscopy (PFM). Electromechanical imaging of tooth dentin and enamel has been performed using PFM with sub-10 nm resolution. Characteristic piezoelectric domain sizes and local protein fiber ordering in dentin have been determined. The shape of a single collagen fibril in enamel is visualized in real space and local electromechanical hysteresis loops are measured. We have also shown that the electromechanical response vector is related to the local molecular orientation and provides an approach for molecular orientation imaging in biological systems. This technique is further used to address several biological systems, including cartilage, antler, bone, and butterfly wing. This approach repeats Galvani's experiment on the nanoscale - 230 years later and with a million times higher resolution. The future opportunities of electromechanical SPM for characterization of complex biological systems are discussed. Research performed as a Eugene P. Wigner Fellow (SVK) at ORNL, managed by UT-Battelle, LLC under DOE contract DCE-AC05-00OR22725. AG acknowledges financial support of the National Science Foundation (Grant No. DMR02-35632).