http://www.mdpi.com/journal/micromachines/special_issues/micromechanics/ Dear Colleagues, As machines continue to be made smaller, there is the requirement for better understanding and control of the materials from which the micromachines are fabricated and the mechanics by which those materials perform. In addition, the engineering of these machines must account for many factors not normally considered in the macro world including size scaling effects on the structural and dynamic characteristics, nonhomogenity and anisotropy of the constituent materials, thermal issues where surface effects can become dominant over bulk effects, the ability to power and control micromachines, and the fundamental and applied mechanics which are basic to the successful evolution of micromachine designs. The special issue on Advances in Micromechanics and Microengineering is expected to bring the latest research results in microscale mechanics and engineering related to the realization of micromachines in the broadest sense. Prof. Dr. Craig R. Friedrich Prof. Dr. Igor Tsukrov Guest Editors{snippet name="submission_info"} http://www.mdpi.com/2072-666X/2/2/129/ The purpose of this paper is to present a simple micromechanics-based model to estimate the effective thermal conductivity of macroscopically isotropic materials of matrix-inclusion type. The methodology is based on the well-established Mori-Tanaka method for composite media reinforced with ellipsoidal inclusions, extended to account for imperfect thermal contact at the matrix-inclusion interface, random orientation of particles and particle size distribution. Using simple ensemble averaging arguments, we show that the Mori-Tanaka relations are still applicable for these complex systems, provided that the inclusion conductivity is appropriately modified. Such conclusion is supported by the verification of the model against a detailed finite-element study as well as its validation against experimental data for a wide range of engineering material systems. http://www.mdpi.com/2072-666X/2/2/129/ Fri, 15 Apr 2011 00:00:00 CEST Micromachines 2011-04-15 2 2 Article 129 149 2072-666X Mori-Tanaka Based Estimates of Effective Thermal Conductivity of Various Engineering Materials 2011-04-15 doi: 10.3390/mi2020129 Jan Stránský Jan Vorel Jan Zeman Michal Šejnoha http://www.mdpi.com/2072-666X/1/3/112/ This paper investigates the design optimization of an electrostatically actuated microcantilever resonator that operates in air. The nonlinear effects of electrostatic actuation and air damping make the structural dynamics modeling more complex. There is a need for an efficient way to simulate the system behavior so that the design can be more readily optimized. This paper describes an efficient analytical approach for determining the optimum design for a microcantilever resonant mass sensor. One simple case is described. The sensor design is a square plate that is coated with a functional polymer and attached to the substrate with folded leg springs. The plate has a square hole in the middle to reduce the effect of squeeze film damping. With the analytical approach, the optimum hole size for maximum sensitivity is found. http://www.mdpi.com/2072-666X/1/3/112/ Tue, 14 Dec 2010 00:00:00 CET Micromachines 2010-12-14 1 3 Article 112 128 2072-666X Optimization Strategy for Resonant Mass Sensor Design in the Presence of Squeeze Film Damping 2010-12-14 doi: 10.3390/microm1010112 Chengzhang Li Michele H. Miller