Influence of SEM vacuum on bone micromechanics using in situ AFM

The mechanical properties of rat bone at micron length scales have been evaluated as a function of environmental conditions using an in situ atomic force microscope (AFM) setup while observing using scanning electron microscopy (SEM). Focused ion beam fabricated rat bone cantilever samples were tested in both low and high vacuum conditions in the SEM as well as wet in air using the AFM to measure their elastic modulus. The elastic modulus of rat bone at micron length scales is shown to be independent of the environmental testing conditions and indicates water is bound to bone material even under relatively high vacuum conditions. Our work therefore shows how in situ mechanical testing of bone while observing using high resolution SEM can provide results similar to testing wet in air.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (310 K)Download as PowerPoint slideHighlights► AFM-SEM in situ technique to mechanically test micro cantilever beams of rat bone. ► Modulus of bone at micron level does not change with vacuum testing conditions. ► Results show water is still bound to bone after two hours in SEM environment. ► In situ SEM observation of hydrated bone micro mechanical testing is possible.