We study the adsorption of polymer chains on a fluctuating surface. Physical examples are provided by polymer adsorption at the rough interface between two non-miscible liquids, or on a membrane. In a mean-field approach, we find that the self–avoiding chains undergo an adsorption transition, accompanied by a stiffening of the fluctuating surface. In particular, adsorption of polymers on a memb...

The helical coiling of plant tendrils has fascinated scientists for centuries, yet the underlying mechanism remains elusive. Moreover, despite Darwin's widely accepted interpretation of coiled tendrils as soft springs, their mechanical behavior remains unknown. Our experiments on cucumber tendrils demonstrate that tendril coiling occurs via asymmetric contraction of an internal fiber ribbon of ...

An invention of a new and novel space robotic manipulator is described. By using a combination of lightweight truss links, a novel hinge joint, tendon-articulation and passive tension stiffening, this new robotic manipulator architecture achieves compact packaging, high strength, stiffness and dexterity while being very lightweight compared to conventional manipulators. The manipulator is also ...

A 3D finite element face model which geometry has been extracted from CT data is being used for implementing orofacial speech gestures and studying underlying muscle activations. This model consists of 3 layers of full and degenerated hexahedral elements. The simplified 5-parameter Mooney-Rivlin hyperelastic law has been used to account for nonlinear elastic properties of face tissues. Contact ...

Endothelial cells (ECs) lining blood vessels express many mechanosensors, including platelet endothelial cell adhesion molecule-1 (PECAM-1), that convert mechanical force into biochemical signals. While it is accepted that mechanical stresses and the mechanical properties of ECs regulate vessel health, the relationship between force and biological response remains elusive. Here we show that ECs...

This paper characterizes the fracture toughness of layer-by-layer (LBL) manufactured thin films with elastic polyurethane, a tough polymer, and poly(acrylic acid) as a stiffening agent. A single-edge-notch tension (SENT) specimen is used to study mode I crack propagation as a function of applied loading. Experimental results for the full-field time histories of the strain maps in the fracturing...

For cellular bodies involving large elastic deformations, mesoscopic continuum models that take into account the interplay between the geometry and the microstructural responses of the constituents are developed, analysed and compared with finite-element simulations of cellular structures with different architecture. For these models, constitutive restrictions for the physical plausibility of t...

This paper focuses on the effect of the viscoelasticity of the adhesive layer on the flexural creep response of reinforced concrete beams strengthened with composite materials. A theoretical model is developed, which considers the strengthened beam as a layered structure that consists of the reinforced concrete beam, the adhesive layer, and the FRP strip, and accounts for the creep of each comp...

Although genetic control of morphogenesis is well established, elaboration of complex shapes requires changes in the mechanical properties of cells. In plants, the first visible sign of leaf formation is a bulge on the flank of the shoot apical meristem. Bulging results from local relaxation of cell walls, which causes them to yield to internal hydrostatic pressure. By manipulation of tissue te...