Mechanics of 1-D Diamond Nanostructures

Project: Research

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Diamond, known as the hardest natural material in the world, is usually considered to bebrittle and undeformable at bulk scale, however their mechanical properties at nanoscalewere less studied. Recently, nanosized diamond structures, or nanodiamonds, haveemerged as a new kind of carbon nanomaterials with many attractive applications inbiomedicine, electronics, photonics etc., but the extremely low deformability and highbrittleness of natural diamonds could potentially hinder their applications whichinvolved larger deformations, such as flexible electronics and bio-nano interfaces.Despite that latest researches showed that diamonds’ hardness and toughness can befurther improved by incorporating nanostructures (Nature 510, 250-253, 2014), such asnanocrystalline and nanotwinned structures, however, instead of being even harder,whether diamond could become more deformable, or even more elastic, whilemaintaining their high hardness/stiffness, should be of great practical and fundamentalinterests. In our preliminary investigations on diamond nanoneedles, a new form of one-dimensional(1-D) diamond nanostructures, we found that nanodiamonds could havesignificantly enhanced elasticity while maintained their ultrahigh strength. In addition,plastic deformation and enhanced hardness than that of bulk diamonds were alsoobserved, while the underlying mechanisms remain unclear. So in this project, we aim toperform systematic nanomechanical study on various single/polycrystalline 1-D diamondnanostructures 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-Dnanostructures of diamond with desired shape, dimensions and crystallographicorientation for different loading geometries”; “quantitative in situ nanomechanicalcharacterizations of the as-fabricated single crystalline samples for their elastic andplastic deformation behavior”; and “investigation on the effects of nanocrystalline grain,nanotwin structure, loading rate/history, and doping in 1-D nanodiamonds as well astheir respective influences on the plasticity and hardness”. The successfulimplementation of this project shall be of importance on the applications of 1-Ddiamond nanostructures in drug/gene delivery, nanophotonics and flexible electronics.The obtained quantitative insights can contribute to the deeper understanding on themechanical behavior and deformation mechanisms of diamond cubic structuredcrystalline materials. The unprecedented mechanical properties, such as enhancedelasticity, of 1-D diamond nanostructures could also open up great opportunities for theemerging “elastic strain engineering” and many functional nanodevice applications.?


Project number9042324
Grant typeGRF
Effective start/end date1/01/1728/06/21

    Research areas

  • nanomechanics , diamond , mechanical properties , nanomaterials , in situ TEM/SEM study