Nanomechanical Material Size Effects Using an In-Situ, On-Chip Test Platform
Accurate measurement of material strength at small scales is of critical importance in the design and manufacture of reliable nano-scale devices. Statistical representations of strength for many nano-scale materials require large numbers of high-precision, repeatable strength tests executed on a platform that is practical to use. The objective of this project is to not only allow large numbers of accurate small-scale strength measurements, but to also advance the understanding of size-related strength effects in specimen sizes down to the nanoscale. To achieve this goal, we will extend the capabilities of an on-chip micro/nanoscale testing platform, allowing the rapid testing of large numbers of specimens of a variety of materials with the capability of in-situ scanning electron microscope (SEM) observation.
This will be a collaborative project led by Carnegie Mellon University (CMU), partnering with Sandia National Laboratories (SNL) and the National Institute of Standards and Technology (NIST). This project will build upon current research at CMU and SNL, supported by Sandia, for initial test platform development. Furthermore, this project will leverage access to unique fabrication facilities located at Sandia, Albuquerque. The PIs will collaborate with NIST researchers who are developing complementary testing approaches and unique localized strain measurement techniques.
The intellectual merit of this research lies in its unique study of nanoscale size effects, which will quantify and provide a fundamental understanding of size-dependent strengths. Coupled with in-situ SEM observation and stress mapping techniques available at NIST, the proposed research will explore the nature of nanoscale material strengths in a way that has not been achieved to date. It will also offer, for the first time, a fundamental basis for designing micro/nanoscale components, fully exploiting the statistical nature of material strengths.
The greatest broader impact of the proposed research will be its development and application of a precision-calibrated testing platform for in-situ observation and testing of large numbers of specimens of nearly any material that can be deposited on polysilicon in thin film form. Despite being the subject of considerable research effort, micro/nanoscale tensile testing techniques have not been developed that allow the high-precision testing of large numbers of specimens. This will be a breakthrough in the microelectromechanical systems (MEMS) and micro/nanoscale materials testing communities, impacting the development of new micro/nano-scale products.
