“…According to this theory, we have the following differential equation for the constitutive response of microtubules. In which σ , C and ε are, respectively, the stress, elasticity and strain tensors; moreover, ∇ 2 and e 0 l c stand for the Laplace operator and nonlocal constant, respectively; also, l c and e 0 are symbols, which are used for calibrating the model and incorporating the effects of the internal configuration of the structure [38,39]. In addition to nonlocal effects, surface influences have a crucial role to play in the mechanics of ultra small structures such as microtubules.…”