Ricerc@Sapienza

Size-dependent structural behavior of inflected Timoshenko elastic nano-beams is investigated by nonlocal continuum mechanics. An innovative stress-driven integral model of elasticity is conceived by swapping source and output fields of Eringen's strain-driven theory. Unlike Eringen's model, the stress-driven nonlocal integral formulation leads to well-posed structural problems. Solution uniqueness and continuous dependence on data are thus ensured.

Size-dependent buckling of compressed Bernoulli-Euler nano-beams is investigated by stress-driven nonlocal continuum mechanics. The nonlocal elastic strain is obtained by convoluting the stress field with a suitable smoothing kernel. Incremental equilibrium equations are established by a standard perturbation technique. Higher-order constitutive boundary conditions are naturally inferred by the stress-driven nonlocal integral convolution, equipped with the special bi-exponential kernel.

This paper presents the development of a multi-hinge, multi-DoF (Degrees of Freedom) nanogripper actuated by means of rotary comb drives and equipped with CSFH (Conjugate Surface Flexure Hinges), with the goal of performing complex in-plane movements at the nanoscale. The design approach, the simulation and a specifically conceived single-mask fabrication process

This paper presents a new NEMS-Technology based device, which transduces micro-metric linear displacements of a tip probe into capacity variations of a rotary comb-drive. The mechanical structure of this device is obtained through three basic steps. Firstly, the pseudo-rigid body equivalent mechanism (PRBM) is obtained by optimizing a straight-line path generator (D-gauge mechanism). Then, the PRBM is transformed into a compliant structure by replacing revolute joints with flexure hinges and by adding a differential comb-drive sensible to variation capacity.