Operational characterization of CSFH MEMS Technology based hinges
13 Mar 2018-Journal of Micromechanics and Microengineering (IOP Publishing)-Vol. 28, Iss: 5, pp 055012
TL;DR: A CSFH has been analyzed with both theoretical and finite element methods, in order to obtain the relation between voltage and generated torque, and showed that CSFH performs better than linear flexure hinges in terms of larger rotations and less stress for given applied voltage.
Abstract: Progress in MEMS technology continuously stimulates new developments in the mechanical structure of micro systems, such as, for example, the concept of so-called CSFH (conjugate surfaces flexural hinge), which makes it possible, simultaneously, to minimize the internal stresses and to increase motion range and robustness. Such a hinge may be actuated by means of a rotary comb-drive, provided that a proper set of simulations and tests are capable to assess its feasibility. In this paper, a CSFH has been analyzed with both theoretical and finite element (FEM) methods, in order to obtain the relation between voltage and generated torque. The FEM model considers also the fringe effect on the comb drive finger. Electromechanical couple–field analysis is performed by means of both direct and load transfer methods. Experimental tests have been also performed on a CSFH embedded in a MEMS prototype, which has been fabricated starting from a SOI wafer and using D–RIE (deep reactive ion etching). Results showed that CSFH performs better than linear flexure hinges in terms of larger rotations and less stress for given applied voltage.
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TL;DR: In this paper, a Computer-Aided Design/Engineering (CAD/CAE) framework for the automatic derivation of accurate pseudo-rigid body (PRB) model parameters is presented for shape optimization of complex-shape flexures.
Abstract: Compliant Mechanisms (CMs) are currently employed in several engineering applications requiring high precision and reduced number of parts For a given mechanism topology, CM analysis and synthesis may be developed resorting to the Pseudo–Rigid Body (PRB) method, in which the behavior of flexible members is approximated via a series of rigid links connected by spring-loaded kinematic pairs From a CM analysis standpoint, the applicability of a generic PRB model requires the determination of the kinematic pairs’ location and the stiffness of a set of generalized springs In parallel, from a design standpoint, a PRB model representing the kinetostatic behavior of a flexible system should allow to compute the flexures’ characteristics providing the desired compliance In light of these considerations, this paper describes a Computer-Aided Design/Engineering (CAD/CAE) framework for the automatic derivation of accurate PRB model parameters, on one hand, and for the shape optimization of complex-shape flexures comprising out-of-plane displacements and distributed compliance The method leverages on the modelling and simulation capabilities of a parametric CAD (ie PTC Creo) seamlessly connected to a CAE tool (ie RecurDyn), which provides built-in functions for modelling the motion of flexible members The method is initially validated on an elementary case study taken from the literature Then, an industrial case study, which consists of a spatial crank mechanism connected to a fully-compliant four-bar linkage is discussed At first, an initial sub-optimal design is considered and its PRB representation is automatically determined Secondly, on the basis of the PRB model, several improved design alternatives are simulated Finally, the most promising design solution is selected and the dimensions of a flexure with non-trivial shape (ie hybrid flexure) is computed This technique, which combines reliable numerical results to the visual insight of CAD/CAE tools, may be particularly useful for analyzing/designing spatial CMs composed of complex flexure topologies
30 citations
TL;DR: A nano-scaled rotary comb drive is herein introduced and obtained using NEMS technology, with an innovative design which takes advantages of the compliant mechanism characteristics.
Abstract: The evolution of microelectronic technologies is giving constant impulse to advanced micro-scaled systems which perform complex operations. In fact, the actual micro and nano Electro-Mechanical Systems (MEMS/NEMS) easily integrate information-gathering and decision-making electronics together with all sorts of sensors and actuators. Mechanical manipulation can be obtained through microactuators, taking advantage of magnetostrictive, thermal, piezoelectric or electrostatic forces. Electrostatic actuation, more precisely the comb-drive approach, is often employed due to its high versatility and low power consumption. Moreover, the device design and fabrication process flow can be simplified by compliant mechanisms, avoiding complex elements and unorthodox materials. A nano-scaled rotary comb drive is herein introduced and obtained using NEMS technology, with an innovative design which takes advantages of the compliant mechanism characteristics. A theoretical and numerical study is also introduced to inspect the electro-mechanical behavior of the device and to describe a new technological procedure for its fabrication.
14 citations
TL;DR: Three grasping-releasing based tasks have been successfully applied to agarose micro beads whose average size is about 60 μm, and the success of the performed tasks rely on the use of a microgripper previously designed, fabricated, and tested.
Abstract: The micromanipulation of micro objects is nowadays the focus of several investigations, specially in biomedical applications. Therefore, some manipulation tasks are required to be in aqueous environment and become more challenging because they depend upon observation and actuation methods that are compatible with MEMS Technology based micromanipulators. This paper describes how three grasping-releasing based tasks have been successfully applied to agarose micro beads whose average size is about 60 μ m: (i) the extraction of a single micro bead from a water drop; (ii) the insertion of a single micro bead into the drop; (iii) the grasping of a single micro bead inside the drop. The success of the performed tasks rely on the use of a microgripper previously designed, fabricated, and tested.
14 citations
Cites methods from "Operational characterization of CSF..."
...The experimental activities described in this paper much owe to the past years, during which a new microgripper has been developed by the team, from the early stage of concept design to the operational testing, through the following phases: design [46–48], optimization [49–51], simulation and control [52], fabrication [53,54], mechanical characterization [55], actuation design [56] and testing [57], and, finally, operational [58] and functional [59–61] testing....
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...Estimated torque exerted by the comb drive Up to 10 −3 μNm [57] Theoretical and Numerical approach....
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TL;DR: 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 is presented.
Abstract: 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 are described in detail and the achieved results are illustrated by SEM images. The first prototype presents a total overall area of (550 × 550) μm2, an active clamping area of (2 × 4) μm2, 600 nm-wide circular curved beams as flexible hinges for its motion and an aspect ratio of about 2.5. These features allow the proposed system to grasp objects a few hundred nanometers in size.
13 citations
Cites background from "Operational characterization of CSF..."
...• mechanism topology for multi-hinge multi-DoF compliant systems [15], which includes connectivity [16] and topological redundancy [17] characteristics; • kinematic synthesis of mechanisms [18], for example the strategy of converting a pseudo-rigid-body equivalent mechanism (PRBM) into a compliant structure with lumped compliance; • testing, operational and measurement [19] capabilities at the micro [20] and nano [21] scale; • structural and multi-physic numerical simulation; • manufacturing processes and peculiar skills in obtaining complex structures [22], even at the nanoscale, such as actuators [23] and grippers [24]....
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TL;DR: In this article, the authors presented the interdisciplinary activities that were necessary to set up an experiment where synthesized SiO2 particles came in contact with the tips of specifically-designed and -fabricated nanomanipulators.
Abstract: Although some recent developments in nanotechnology made the prospects of a direct mechanical manipulation of micro- or nano-objects quite realistic, there are still several concerns and difficulties that affect such an endeavor. This is probably due to the large base of knowledge that is necessary to approach the problem of handling a nano-object by means of a nano- or micro-device. Therefore, any progress in this field is possible only by means of an integrated and interdisciplinary approach, which takes into account different aspects of the phenomenon. During the actual pioneering phase, there is a certain convenience in handling nano-objects that: (a) have peculiar known characteristics; (b) are easily recognizable, and (c) are interesting to the scientific community. This paper presents the interdisciplinary activities that were necessary to set up an experiment where specifically synthesized SiO2 particles came in contact with the tips of specifically-designed and -fabricated nanomanipulators. SiO2 mesoporous nanoparticles (KCC-1), having a peculiar dendritic structure, have been selected as a suitable nano-object because of the possibility to easily modulate their morphology. The expected contact force has been also calculated by means of Finite Element Analysis (FEA) electro-mechanical simulations.
10 citations
References
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308 citations
07 Aug 2002
TL;DR: It is emphasized that the precise modeling of a flexure hinge is significant to guarantee the positional accuracy of parallel micromechanisms using Flexure hinge.
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216 citations
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164 citations
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158 citations
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121 citations