The research objective of this award is to contribute to the scientific understanding of the mechanisms of the mechanical response of soft polymer materials so as to permit the design and construction of effective micro/nano structures and devices for biomedical applications. Elastic and viscoelastic characterization and modeling of a soft polymer material, namely polydimethylsiloxane (PDMS), will be performed. Such a polymer material will be probed at different scales from bulk down to the micro/nano levels using punch tests, and nanoindentation techniques. The results will be implemented into a viscoelastic finite element analysis model developed in tandem. The validated model will ultimately be utilized to determine the mechanical forces of living cells from the measured deflection of PDMS pillar arrays. To this end, the proposed research would entail a balance between characterization of the viscoelastic material and the development of a theoretical or numerical viscoelastic modeling for cellular force measurement applications.
The scientific insights from the in-depth study of the viscoelasticity of PDMS will contribute to the analysis of many other soft polymer materials at micro/nano scales commonly used in biomedical industries. The vision is to expand the science and engineering community's capacity to probe soft polymer materials at small scales by developing both new theoretical models and experimental methodologies. These characterization techniques and platforms will allow scientists to ask profound and previously intractable questions related to biomedical research, and to obtain quantitative empirical answers with resolution sufficient to characterize the soft materials in small scales. This award will implement and disseminate an educational and training program that develops interdisciplinary modes of thought at the boundary of bio- and nano-mechanics through integrated research opportunities in micro/nano characterization of soft polymer materials. The project will incorporate undergraduate and graduate research, graduate education at both institutions and also outreach to high-school students.