SBIR Phase I: High-resolution high-speed dynamic nanoindenter to measure viscoelastic properties of soft materials

This Small Business Innovation Research Phase I project is aimed at testing the feasibility of a new technology for studying the mechanical properties of soft materials, such as biomaterials, cells, tissues, polymers, and nanocomposites. The proposed method will provide substantially higher spatial resolution and increase the speed of mapping viscolelastic properties of soft materials, by a factor of more than 100 versus existing technology. In addition, the proposed technique will give users the ability to test the linearity of strain-stress relation at the nanoscale while performing the measurements (such linearity information is paramount for proper calculation of the rigidity modulus). We will analyze viscoelastic (frequency-dependent) properties of materials with a nanoscale probe through atomic force microscopy (AFM), by measuring multiple frequencies at the same time (rather than sequentially, as is currently done in existing nanoindenters). This will accelerate the measurements for any material, but will also represent a true breakthrough for materials research. Besides increased measurement speed, a substantially higher spatial resolution will be attached because there will be no need to wait for the slow relaxation of soft materials (a phenomenon called "creep"). The broader impact/commercial potential of this project will be to enable mapping of mechanical viscoelastic properties of soft materials with dramatically improved spatial resolution and speed (by more than a factor of 100) as compared to existing nanoindenters. This will add a new dimension to the study of the nanomechanics of polymers, nanocomposites, biomaterials, and tissues at the nanoscale. This solution will be commercially valuable for the users of nanoindenters (representing a $50 million market in 2010) and AFMs (representing a market of more than half a billion dollars). More broadly, this tool will be invaluable for researchers working in the areas of bio-nanotechnology (~$100-150 billion), biomaterials ($25 billion), and polymers ($200+ billion). The work done in this effort will result in the development of an attachment (both hardware and software) for existing AFMs, and eventually, as a stand-alone system to measure the unique spectra of viscoelastic properties of soft materials.