The remarkable optoelectronic and especially photovoltaic performance of hybrid organic–inorganic perovskite (HOIP) materials drives efforts to connect materials properties to this performance. From nano-indentation experiments on solution-grown single crystals we obtain elastic modulus and nano-hardness values of APbX3 (A = Cs, CH3NH3; X = I, Br). The Young's moduli are ~14, 19.5, and 16 GPa, for CH3NH3PbI3, CH3NH3PbBr3, and CsPbBr3, respectively, lending credence to theoretically calculated values. We discuss the possible relevance of our results to suggested “self-healing”, ion diffusion, and ease of manufacturing. Using our results, together with literature data on elastic moduli, we classified HOIPs amongst the relevant material groups, based on their elastomechanical properties.

We used atomic force microscope (AFM) to acquire high-resolution images of collagen type I triple-helices under ambient conditions in tapping mode. Angles between consecutive fixed-length segments were measured and analyzed to yield persistence length and elastic constant. Changing the segment length allowed exploring the mechanics at various scales. Understanding the mechanical properties of collagen molecules could serve to elucidate mechanisms of complex mechanical properties of interest in nanomedicine and nanotechnology.

We report here a finite element simulation of the compression of inorganic WS2 hollow nanoparticles. The particle was modeled as a multilayered polyhedron to investigate the effect of the unique onion-like and highly faceted structure in the mechanical response. The simulation revealed the central role of the faceted structure of the WS2 nanoparticles in the mode of failure. The stress magnitude and distribution was shown to be size dependent, as predicted from previously published experimental results. Moreover, the simulation points to the influence of the layered structure on the energy release during compression loading via interlayer shear.

Nickel-titanium (NiTi) alloys combine several remarkable characteristics, among them are shape-memory, superelasticity, great strain recovery, good biocompatibility, and corrosion resistance. These render them well suited to a wide range of medical applications, such as cardiovascular stents, laparoscopy, and dental applications such as NiTi endodontic files (EFs) used for root canal treatment, which are the focus of this work. Unfortunately, fatigue-induced and incidental failure of NiTi EFs is not uncommon, which may lead to severe medical consequences. Here we examine the effects of cobalt coatings with impregnated fullerene-like WS2 nanoparticles on file fatigue and failure. Dynamic x-ray diffraction, nanoindentation and torque measurements all indicate a significant improvement in the fatigue resistance and time to breakage of the coated files, stemming from reduced friction between the file and the surrounding tissue. These methods are possibly applicable to a variety of NiTi-based medical devices where fatigue and consequent failure are of relevance.

Individual multi-walled carbon nanotube pullout experiments were used to measure the adhesion strength at a nanotube-epoxy polymer interface. The interfacial strength was found, as expected, to increase when the nanotubes were chemically treated to induce strong bonding with the polymer matrix. At long nanotube embedment lengths within the polymer, the nanotubes were seen to fracture in preference to failure at their interface with the polymer. Interfacial mechanics models are applied to the data to describe interfacial adhesion at the nano-level.

The wetting properties and surface characteristics of individual carbon nanotubes are elucidated by immersing the nanotube into various organic liquid. The resultant force acting on the nanotube can be used to evaluate a liquid contact angle at the nanotube surface from classical methods. This technique was shown to be accurate enough to discern differences in wetting behavior due to both structural and chemical changes in the nanotube structure.

An atomic force microscope, operated in ultra-high vacuum has been employed to study the tribological properties of diamond films under small loads (< 10−6 N) on a nanometer scale. The incidence of intermittent motion, “stick-slip”, while sliding a diamond tip across the diamond film, is detected under certain experimental conditions and is discussed with respect to the difference between static and kinetic friction, sample topography and a varying sample condition.

A new UHV atomic force microscope for the study of micromechanical properties is described. A capacitance technique is used, which enables simultaneous measurement of forces perpendicular and parallel to the surface (i.e., load and friction), and has low noise down to frequencies below 0.1 Hz. Preliminary results for Ir- and W-tips sliding on graphite and silicon, respectively, demonstrate the capabilities of this new instrument.