Characterization of mechanical and rheological properties of materials at macro and nano scales

The recent proliferation of nano technology has generated much interest in the properties of materials with reduced size, and substantial effort has been made into the study of material properties at the nanoscale over the past several decades. Different techniques were used to examine the material behaviors under confinement; however the reported changing apparent material properties, such as modulus and glass transition temperature, are not universal and can dependent on test techniques and test conditions. There is still a lack of complete understanding about the characterization for the material behaviors at a small scale and the underlying physics for the reported behaviors. One obstacle is that conventional macroscopic measurement methods cannot be used and accurate characterization demands highly specialized measurement and sophisticated analysis techniques as the size scale of the test specimen goes into the nano meter. The main emphasis of this research is the study of how to probe material behavior at the nanometer size. We provide results from novel techniques, new analysis methods, and new materials in our investigations of the rheological properties at the nanoscale. The results are compared with the macroscopic properties. The goal is built upon past developments from these laboratories in order to give better understanding of material behaviors at different size scales, and to develop a comprehensive picture of needs for future research.