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Elasto-capillarity is the ability of capillary force to deform an elastic material. From the viewpoint of mechanics, elastocapillarity phenomena essentially involve competition between the elastic strain energy in the bulk and the energy on the surfaces/interfaces. In the modeling of these phenomena, some challenging issues are, among others, the exact characterization of energies at the micro scale, the solution of strongly nonlinear problems of structures with large deformation and moving boundary conditions, and instability of either solid structures or droplets/films.The capillary forces are generally negligible in the analysis of macroscopic structures but often play a significant role in many phenomena at small scales.〔Liu, Jian-Lin, and Xi-Qiao Feng. "On elastocapillarity: A review." Acta Mechanica Sinica 28.4 (2012): 928-940.〕 == Bulk elasticity == When depositing a droplet on a solid surface with contact angle θ, horizontal force balance was described by Young's equation. However, there is a vertical force balance which often ignored can be written as: Fvertical=γ×sinθ= E×δ Where Fvertical is the force perunit length in the vertical direction γ is the surface tension of a liquid E is the Young's modulus of a substrate δ is deformation of the substrate This gives length scale δ~ γ/E sinθ for the deformation of bulk materials caused by the surface tension force. For example, if a water (γ ~ 72 mN/m) is deposited on the glass (E~ 700 GPa), this gives δ~10−12m which is typically negligible. However, if a water is deposited on the PDMS (E ~ 300 kPa), this caused the deformation to be δ~10−6m, which is in micron scale, this can have great impact on the micro/nanotechnology applications where length scale is comparable and "soft" photoresists were used. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Elasto-capillarity」の詳細全文を読む スポンサード リンク
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