This Small Business Innovation Research (SBIR) Phase II project will develop technologies to enable commercialization of nanoscale Dynamic Mechanical Analysis (DMA). Conventional DMA works by applying an oscillating stress to a sample and measuring the time-dependent strain. Analysis of DMA data gives information about material stiffness, viscosity, thermal transitions and activation energies, for example. DMA is a critical and widely used tool to measure the viscoelastic properties of bulk materials, but it suffers from three key limitations: slow speed, limited frequency range, and the lack of spatially-resolved information. Large and growing material classes employ nanoscale composite structures to achieve desired material properties. No current tool can rapidly examine the temperature-dependent viscoelastic response of these materials on the scales they are being engineered. To address this unmet need, we will extend successful Phase I research to develop instrumentation based on atomic force microscopy (AFM) using rapidly heatable AFM cantilever probes. Specifically, the nanoscale DMA platform will provide: (1) variable temperature DMA in seconds; (2) measurement frequencies three orders of magnitude higher than conventional DMA; (3) spatial resolution down to < 100 nm; and (4) sensitive and spatially-resolved measurements of glass transitions on wide range of commercially important polymers not previously measurable.
The broader impact/commercial potential of this project will stretch across multiple industries and academic research areas. Metrology and characterization are foundations of successful materials science and materials manufacturing. The lack of materials characterization tools at the nanoscale has been identified by the chemical industry as a key bottleneck for the rapid development of new materials. This proposal aims to fill a major gap in required instrumentation. With the ability to measure temperature-dependent viscoelastic properties at the nanoscale, materials scientists and engineers will be able for the first time to directly investigate local material stiffness, energy absorption, and damping in heterogeneous materials over a wide range of operating temperatures and frequencies. In addition to spatially resolved measurements, the dramatic measurement speed improvements (a thousand-fold improvement over conventional DMA) will enable higher measurement throughput, lower cost per measurement, more frequent sampling and better measurement statistics. Based on interactions with customers in diverse industries, we have already has already identified strong market pull in areas including epoxies, polymer blends, multilayer films, medical devices, semiconductor packaging, and aerospace markets.
