Matteo Verotti

Bio: Matteo Verotti is an academic researcher from Sapienza University of Rome. The author has contributed to research in topics: Compliant mechanism & Isotropy. The author has an hindex of 17, co-authored 45 publications receiving 741 citations. Previous affiliations of Matteo Verotti include Canadian Real Estate Association & University of Genoa.

Active isotropic compliance in redundant manipulators

Abstract: The isotropic compliance property is examined in the Special Euclidean Group SE(3) in the case of redundant manipulators. The redundancy problem is solved by means of the QR decomposition of the transposed Jacobian matrix, and the compliance property is achieved by means of active stiffness regulation. Thanks to the defined control matrices, the control system realizes the isotropy condition. The local optimization of the joint torques is discussed. In particular, the joint control torques work is minimized obtaining an analytic solution through a Lyapunov equation. The proposed approach is applied to a 7R and to a 9R serial manipulator, and verified by means of multibody dynamics simulations.

Energy Harvesting From Base Excitation of a Biomimetic Fish Tail Hosting Ionic Polymer Metal Composites

Abstract: In this study, we seek to understand the feasibility of energy harvesting from the tail beating motion of a fish through active compliant materials. Specifically, we analyze energy harvesting from the undulations of a biomimetic fish tail hosting ionic polymer metal composites (IPMCs). The design of the biomimetic tail is specifically inspired by the morphology of the heterocercal tail of thresher sharks. We propose a modeling framework for the underwater vibration of the biomimetic tail, wherein the tail is assimilated to a cantilever beam with rectangular cross section. We focus on base excitation in the form of a superimposed rotation about a fixed axis and we consider the regime of moderately large–amplitude vibrations. In this context, the effect of the encompassing fluid is described through a nonlinear hydrodynamic function. The feasibility of harvesting energy from an IPMC attached to the vibrating structure is assessed and modeled via an electromechanical framework. Experiments are performed to validate the theoretical expectations on energy harvesting from the biomimetic tail.© 2013 ASME

Position accuracy criteria for planar flexural hinges

Abstract: With the increasing implementation of compliant mechanisms in high-precision and high-accuracy applications, the need to evaluate the positioning performance of the flexure hinges becomes evident. In this paper, the determination of the accuracy of planar flexures is addressed by analyzing and comparing the available criteria presented in literature, including a new criterion based on the pole of the displacements. For uniform flexures, an analytical formulation is developed for end-moment loads, whereas complex loading conditions, resulting in an inflection point, are analyzed and numerically evaluated. The accuracy criteria are also applied for analyzing the positioning performance of the cross-axis flexural pivot. Various relations among the different criteria are determined, and their limitations, such as the non-bijective correspondence with the deformed configurations, are discussed. The criteria are applied to the design of a high-accuracy cross-axis pivot.

A genetic algorithm for the estimation of viscoelastic parameters of biological samples manipulated by mems tweezers

Abstract: In this paper, a novel technique for the viscoelastic characterization of biosamples is presented. The measuring tool consists of MEMS-technology based tweezers that are used, in general, to perform micromanipulation tasks. A mechanical model is developed for the nonlinear dynamics of the microsystem, composed of the tweezers and of the sample to be analyzed. The Maxwell liquid drop constitutive law is considered for the sample. The identification of the viscoelastic parameters is performed by implementing a genetic algorithm.

Some Basic Problems Of The Mathematical Theory Of Elasticity

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Mechanics and electrochemistry of ionic polymer metal composites

Abstract: Ionic polymer metal composites (IPMCs) are electroactive materials composed of a hydrated ionomeric membrane that is sandwiched between noble metal electrodes. Here, we propose a modeling framework to study quasi-static large deformations and electrochemistry of IPMCs. Specifically, IPMC kinematics is described in terms of its mechanical deformation, the concentration of mobile counterions neutralizing the ionomer, and the electric potential. The chemoelectromechanical constitutive behavior is obtained from a Helmholtz free energy density, which accounts for mechanical stretching, ion mixing, and electric polarization. The three-dimensional framework is specialized to plane bending of thin IPMCs. Hence, we propose a structural model, where the moment and the charge stored along the IPMC are computed from the solution of a modified Poisson–Nernst–Planck system, in terms of the through-the-thickness coordinate. For small static deformations, we present a semianalytical solution based on the method of matched asymptotic expansions, which is ultimately used to study IPMC sensing and actuation. We demonstrate that the linearity of IPMC actuation in a broad voltage range could be attributed to the interplay of two competing nonlinear phenomena, associated with Maxwell stress and osmotic pressure. In agreement with experimental observations, our model confirms the possibility of tailoring IPMC actuation by varying the counterion size and the concentration of fixed ions. Finally, the model is successful in predicting the significantly different voltage levels displayed by IPMC sensors and actuators, which are associated with remarkable variations in the ion mixing and polarization energies.

Robotic Micromanipulation: Fundamentals and Applications

Abstract: Robotic micromanipulation is a relatively young field. However, after three decades of development and evolution, the fundamental physics; techniques for sensing, actuation, and control; tool sets ...