In our group, we aim to understand defect-interface interactions by pioneering research into composites where the interfaces between constituents dominate mechanical behavior. Such interfaces influence not only the unit processes of single dislocations that can be understood at the atomic scale, but also mechanical behavior at the scales of a few to tens of dislocations and the resulting bulk behavior. This class of materials encompasses those containing chemical gradients and/or boundary curvature such as layered composites or composites with 3D character. Detailed work into the defect-interface interactions enabling the enhanced mechanical behavior of two-phase or multiphase materials have only begun to investigate the rich parameter space of interface character, morphology, and chemistry.

Materials that are exposed to radiation environments such as those found in nuclear reactors undergo changes in microstructure that can lead to both hardening and embrittlement, limiting their useful lifetimes. Nanomechanical testing can offer a low cost mechanical characterization method for testing irradiated materials. For example, significant throughput is gained by coupling ion-irradiation and nanoindentation to screen candidate materials without the need for costly post-irradiation examination facilities. The limited penetration of ion irradiation in metals necessitates the use of nano/microscale methodologies to determine mechanical behavior. In the case of neutron irradiated materials which are still radioactive, the cost and dose can be significantly reduced by working with very small amounts of material. We apply nanomechanical test protocols to characterize the differences in mechanical response between microstructures containing irradiation-induced defects such He-bubbles and/or dislocation loops in ion irradiated metallic materials, and accelerate the development of new alloys for service under irradiation extremes.

Nanomechanical property analysis of pharmaceutical molecular crystals is crucial for understanding and optimizing drug formulation and manufacturing processes. This analysis involves techniques such as nanoindentation and atomic force microscopy to measure properties like elastic modulus, hardness, and fracture toughness at the nanoscale. These properties influence important characteristics of drug crystals, including tableting behavior, dissolution rates, and stability during storage and transport. By examining the nanomechanical properties of different crystal faces and polymorphs, researchers can gain insights into structure-property relationships and develop strategies to enhance drug performance and processability. This knowledge is particularly valuable for improving the efficacy and stability of solid dosage forms in the pharmaceutical industry.

There is a need for rapid throughput test techniques that can foreshorten the time from lab bench to industrial application and the connectivity to improve alloy performance resistance to fracture and failure. Nano and micromechanical test techniques including indentation, uniaxial straining, and cantilever or three point bending are particularly important in cases where macroscopic test specimens are either impossible or inappropriate. Examples include coatings, microelectronics, thin films, MEMS devices, and implantable prostheses which cannot be replicated at larger length scales or in other geometries. Our micromechanical methods overcome the inherent limitations of macroscopic testing currently employed to generate mechanical property data, and understand the influence of processing on microstructure and mechanical response. Current projects include the high-throughput mechanical property mapping of materials, and innovative approaches to determining fracture behavior.