Indentation tests can be used to characterize the mechanical properties of bone at small load/length scales offering the possibility of utilizing very small test specimens, which can be excised using minimally-invasive procedures. In addition, the need for mechanical property data from bone may be a requirement for fundamental multi-scale experiments, changes in nano- and micro-mechanical prope...

The elastic properties of micrometer-sized hollow colloidal particles obtained by emulsion templating are probed by nanoindentation measurements in which point forces are applied to solvent-filled particles supported on a flat substrate. We show that the shells respond linearly up to forces of 7-21 nN, where the indentation becomes of the order of the shell thickness (20-40 nm). In the linear r...

Glasses are lucrative engineering materials owing to their superior mechanical properties such as high strength and large elastic strain. A central question concerns incipient plasticity - the onset of permanent deformation - that is central to their relaxation, aging, yield and fracture. Here, we use an analogue of nano-indentation performed on a colloidal glass to obtain direct images of the ...

Though brittle, silicate glasses undergo plastic deformation at the microscopic scale. Mechanical contact and indentation are the most common situations of interest. The plasticity of glasses is characterized not only by shear flow but also by a permanent densification process. After indentation, densification can locally reach 20% in a pure silica glass. In this paper, a new constitutive model...

Results are reported from two molecular-dynamics simulations designed to yield insight into the engineering of nanometre-scale structures. The first is the initial stages of the indentation of a silicon substrate by an atomically-sharp diamond tip. Up to an indentation depth of approximately 0.6 nm the substrate responds elastically and the profile of the disturbed region of the substrate norma...

We have analyzed by transmission electron microscopy silicon and GaAs crystals polished with sandpapers of different grain size. The surface damage induced a crystal permanent convex curvature with a radius of the order of a few meters. The curvature is due to a compressive strain generated in the damaged zone of the sample. Contrary to what was reported in the literature, the only defects dete...

Genetically-engineered collagen peptides were assembled into freestanding films when QDs are co-assembled as joints between collagen domains. These peptide based films show excellent mechanical properties with Young's modulus of ~20 GPa, much larger than most of multi-composite polymer films and previously reported freestanding nanoparticle-assembled sheets, and it is even close to the bone tis...

In computer programming languages, indentation formats program source code to improve readability. Programming languages make use of indentation to define program structure .Programmers use indentation to understand the structure of their programs to human readers. Especially, indentation is the better way to represent the relationship between control flow constructs such as selection statement...