Mechanics of 1-D Diamond Nanostructures
DescriptionDiamond, known as the hardest natural material in the world, is usually considered to be brittle and undeformable at bulk scale, however their mechanical properties at nanoscale were less studied. Recently, nanosized diamond structures, or nanodiamonds, have emerged as a new kind of carbon nanomaterials with many attractive applications in biomedicine, electronics, photonics etc., but the extremely low deformability and high brittleness of natural diamonds could potentially hinder their applications which involved larger deformations, such as flexible electronics and bio-nano interfaces. Despite that latest researches showed that diamonds’ hardness and toughness can be further improved by incorporating nanostructures (Nature 510, 250-253, 2014), such as nanocrystalline and nanotwinned structures, however, instead of being even harder, whether diamond could become more deformable, or even more elastic, while maintaining their high hardness/stiffness, should be of great practical and fundamental interests. In our preliminary investigations on diamond nanoneedles, a new form of one-dimensional (1-D) diamond nanostructures, we found that nanodiamonds could have significantly enhanced elasticity while maintained their ultrahigh strength. In addition, plastic deformation and enhanced hardness than that of bulk diamonds were also observed, while the underlying mechanisms remain unclear. So in this project, we aim to perform systematic nanomechanical study on various single/polycrystalline 1-D diamond nanostructures with well-defined orientations, geometries and loading mechanisms, assisted with our high-resolution in situ electron microscopy (SEM/TEM) characterization techniques.This project involved with three major parts, including the “rational fabrications of 1-D nanostructures of diamond with desired shape, dimensions and crystallographic orientation for different loading geometries”; “quantitative in situ nanomechanical characterizations of the as-fabricated single crystalline samples for their elastic and plastic deformation behavior”; and “investigation on the effects of nanocrystalline grain, nanotwin structure, loading rate/history, and doping in 1-D nanodiamonds as well as their respective influences on the plasticity and hardness”. The successful implementation of this project shall be of importance on the applications of 1-D diamond nanostructures in drug/gene delivery, nanophotonics and flexible electronics. The obtained quantitative insights can contribute to the deeper understanding on the mechanical behavior and deformation mechanisms of diamond cubic structured crystalline materials. The unprecedented mechanical properties, such as enhanced elasticity, of 1-D diamond nanostructures could also open up great opportunities for the emerging “elastic strain engineering” and many functional nanodevice applications.?
|Effective start/end date||1/01/17 → …|
- nanomechanics , diamond , mechanical properties , nanomaterials , in situ TEM/SEM study