ARRA: MRI-R2: Instrument Acquisition: Nanomechanical Systems for In Situ Mechanical Characterization of Materials in Application Environments

In situ nanomechanics is an emerging scientific research endeavor that is critical to the state-of-the-art materials research. We propose to acquire several complementary instruments to establish a strong capability in micro- and nano-characterization of mechanical behavior of materials in controlled environments and under external stimuli. Specifically, we plan to acquire a nanoindenter and a nano-impact/fatigue tester capable of operating in controlled temperatures, controlled gas, and liquid compositions while under thermal, electrical, electrochemical, and biological stimuli. The proposed instruments will enable and enhance several research and education activities, including understanding and developing (1) new materials for electrochemical energy storage, (2) lightweight materials for aerospace and automotive applications, (3) lead-free soldering for electronic interconnects, micro-electromechanical devices (MEMS), and micro-fluidic devices, and (4) biomaterials and multi-functional, smart materials for biomedical applications. Advancing fundamental understanding in these technology areas requires measurement of mechanical behavior of functional and structural materials under cyclic stimuli, surface and near surface properties of thin films and coatings, biological samples, and implantable devices. Many of these measurements need to be conducted in controlled environments under which external stimuli can change molecular structure, sample morphology, and physical and chemical properties. For example, measurements of mechanical properties in inert atmospheres under electrochemical potentials are necessary for developing novel materials for lithium ion batteries. Development of shape memory alloys, shape memory polymers, and composites requires mechanical property measurements under specified time-temperature history and loading paths. Biomaterials research requires mechanical characterization of soft materials in contact with biological fluids that are subjected to electrical impulses and other external fields. The development of the next generation of lead-free solders for micro- and nano-electronics will depend on their responses to coupled thermalmechanical- electrical stimuli.