Computer Solution of Linear Algebraic Systems. By G. Forsythe and C. B. Moler. Pp. xi, 148. 1967. (Prentice-Hall.)

Thank you for downloading some basic problems of the mathematical theory of elasticity. As you may know, people have search hundreds times for their favorite readings like this some basic problems of the mathematical theory of elasticity, but end up in infectious downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they cope with some infectious bugs inside their computer.

Some Basic Problems Of The Mathematical Theory Of Elasticity

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.

Mechanics and electrochemistry of ionic polymer metal composites

A Review on Compliant Joints and Rigid-Body Constant Velocity Universal Joints Toward the Design of Compliant Homokinetic Couplings

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 ...

Robotic Micromanipulation: Fundamentals and Applications

Biogas production from anaerobic digestion has increased rapidly in the last years, in many parts of the world, mainly due to its local scale disposition and to its potential on greenhouse gases (GHG) emissions mitigation. Biogas can be used as fuel for combined heat and power systems (CHP), in particular for internal combustion engines (ICEs). In recent investigations, fuel cells have been considered as alternative CHP systems. In the present article, two different energy conversion systems are compared: a 1.4 MW class MCFC system, running on pipeline natural gas, and an in situ ICE, running on biogas. In the first case, biogas is considered as a source fuel to obtain upgraded gas to be injected in the natural gas grid. In such scenario, the location of the fuel cell power plant is no longer strictly connected to the anaerobic digester site. Several energy balances are evaluated, considering different upgrading techniques and different biogas methane/carbon dioxide ratios.

Biogas upgrading and utilization from ICEs towards stationary molten carbonate fuel cell systems

This paper presents a method for detecting the mechanical stiffness of micro-metric biological tissues by means of compliance tests performed with a MEMS-Technology based microgripper. Thanks to an actuating rotary comb drive working in cooperation with another sensing rotary comb drive, the system is able to recognize the tissue sample stiffness. Such characterization is possible thanks to a proper control system that is applied to the whole mechanical structure.

Stiffness Characterization of Biological Tissues by Means of MEMS-Technology Based Micro Grippers Under Position Control

This paper describes the design, simulation, construction process and experimental analysis of a microgripper, which makes use of a new concept hinge, called CSFH (Conjugate Surfaces Flexure Hinge). The new hinge combines a curved cantilever beam, as flexible element, and a pair of conjugate surfaces, whose contacts depend on load conditions. CSFH hinges improve accuracy and guarantee that minimum stress conditions hold within the flexible beam. This microgripper is designed for Deep Reactive-Ion Etching (D-RIE) construction process and comb-drive actuation. Theoretical basis and Finite Element Analysis (FEA) simulations have been employed in order to predict the feasibility of the device under construction. Finally, some experimental evidence of the construction process has been provided.

Development of a MEMS technology CSFH based microgripper

This paper deals with the manipulation of micro-objects operated by a new concept multi-hinge multi-DoF (degree of freedom) microsystem. The system is composed of a planar 3-DoF microstage and of a set of one-DoF microgrippers, and it is arranged is such a way as to allow any microgripper to crawl over the stage. As a result, the optimal configuration to grasp the micro-object can be reached. Classical algorithms of kinematic analysis have been used to study the rigid-body model of the mobile platform. Then, the rigid-body replacement method has been implemented to design the corresponding compliant mechanism, whose geometry can be transferred onto the etch mask. Deep-reactive ion etching (DRIE) is suggested to fabricate the whole system. The main contributions of this investigation consist of (i) the achievement of a relative motion between the supporting platform and the microgrippers, and of (ii) the design of a process flow for the simultaneous fabrication of the stage and the microgrippers, starting from a single silicon-on-insulator (SOI) wafer. Functionality is validated via theoretical simulation and finite element analysis, whereas fabrication feasibility is granted by preliminary tests performed on some parts of the microsystem.

Design and Validation of a Single-SOI-Wafer 4-DOF Crawling Microgripper

The mechanical characterization of biological samples is a fundamental issue in biology and related fields, such as tissue and cell mechanics, regenerative medicine and diagnosis of diseases. In this paper, a novel approach for the identification of the stiffness and damping coefficients of biosamples is introduced. According to the proposed method, a MEMS-based microgripper in operational condition is used as a measurement tool. The mechanical model describing the dynamics of the gripper-sample system considers the pseudo-rigid body model for the microgripper, and the Kelvin–Voigt constitutive law of viscoelasticity for the sample. Then, two algorithms based on recursive least square (RLS) methods are implemented for the estimation of the mechanical coefficients, that are the forgetting factor based RLS and the normalised gradient based RLS algorithms. Numerical simulations are performed to verify the effectiveness of the proposed approach. Results confirm the feasibility of the method that enables the ability to perform simultaneously two tasks: sample manipulation and parameters identification.

https://www.mdpi.com/2076-0825/7/4/74/pdf

Matteo Verotti

Papers

Biogas upgrading and utilization from ICEs towards stationary molten carbonate fuel cell systems

Stiffness Characterization of Biological Tissues by Means of MEMS-Technology Based Micro Grippers Under Position Control

Development of a MEMS technology CSFH based microgripper

Design and Validation of a Single-SOI-Wafer 4-DOF Crawling Microgripper

Recursive Least Squares Filtering Algorithms for On-Line Viscoelastic Characterization of Biosamples