Continuing technological advancement of mechanical characterization at the microscale has enabled the isolation of micron-sized specimens and their direct mechanical characterization. Such techniques, initially developed for engineering materials and MEMS, can also be applied on hard biological materials. Bone is a material with a complex hierarchical structure ranging from the macro- all the way down to the nanoscale. To fully understand bone tissue mechanics, knowledge of the mechanics of all structural elements i.e. at every length scale is necessary. Particularly, the mechanical properties of microstructural elements, such as bone lamellae are still largely unknown. In the last decade, testing protocols have been devised to close this gap including bending and compression of micrometer-sized bone specimens. However, the precision and accuracy of results obtained have not been discussed. In this study, we aim to do exactly this: we validate microbeam bending by testing silicon microbeams with known mechanical constants, and evaluate the precision and sources of errors in both microbeam bending and micropillar compression by means of finite element (FE) modeling. Bending of Si-microbeams reproduced the expected value for the bending modulus within 17% accuracy, although the effect of geometrical uncertainties was estimated to result in relative errors of up to 50%. The deformation of constraining bulk material had a smaller influence, with relative errors of 11%, for microbeam bending and 25% for micropillar compression. For the latter this error could be sufficiently eliminated by the Sneddon correction. The tapering of micropillars had a negligible effect on overall apparent stiffness, but induced inhomogeneous stress state within micropillars may lead to superposed structural deformation mechanisms and be responsible for failure patterns observed in past studies.

在微尺度上机械表征的持续技术进步使微米级样品的分离及其直接机械表征成为可能。最初为工程材料和MEMS开发的此类技术也可以应用于硬生物材料。骨骼是一种具有复杂的层次结构的材料，其范围从宏观到纳米。为了充分理解骨骼组织力学，必须了解所有结构要素（即每个长度尺度）的力学。特别地，诸如骨薄片的微结构元件的机械性能仍是很大程度上未知的。在过去的十年中，已经设计出了一些测试方案来缩小这一差距，包括弯曲和压缩微米级骨标本。然而，尚未讨论获得的结果的准确性和准确性。在这项研究中，我们旨在做到这一点：我们通过测试具有已知机械常数的硅微束来验证微束弯曲，并通过有限元（FE）建模来评估微束弯曲和微柱压缩的精度和误差来源。硅微梁的弯曲再现了弯曲模量的预期值，精度在17％以内，尽管估计几何不确定性的影响会导致相对误差高达50％。约束散装材料的变形影响较小，相对于微梁弯曲的相对误差为11％，相对于微柱压缩的相对误差为25％。对于后者，可以通过Sneddon校正充分消除此错误。