Articulated MEMS Robot for Microfactory Applications

Volume 6: ASME Power Transmission and Gearing Conference; 3rd International Conference on Micro- and Nanosystems; 11th International Conference on Advanced Vehicle and Tire Technologies ◽

10.1115/detc2009-86888 ◽

2009 ◽

Cited By ~ 1

Author(s):

Rakesh Murthy ◽

Dan O. Popa

Keyword(s):

Range Of Motion ◽

Experimental Characterization ◽

Micro Electro Mechanical Systems ◽

End Effector ◽

Nano Indentation ◽

Experimental Identification ◽

Work Volume ◽

Out Of Plane ◽

Flexure Joints

A MEMS (Micro Electro Mechanical Systems) based four degree of freedom articulated microrobot is presented as an example of next generation miniaturized top down manipulators. The robot occupies 6mm3 in total volume with room for further down scaling. The operating work volume is 50μm × 50μm × 75μm with a 2P2R (Prismatic Prismatic Revolute Revolute) kinematic configuration — X, Y, Pitch and Yaw. The presented microrobot design rises above commonly encountered performance tradeoff’s of previous MEMS positioners such as range of motion vs. exerted force and range of motion vs. precision. It is constructed using a combination of hybrid microassembly and high aspect ratio micromachining. Structurally, the first version of the microrobot consists of Silicon 2 1/2 D parts and a 30μm diameter Cu wire. The robot joints and attachment of the end effector are accomplished by microassembly using compliant snap-fasteners, monolithic flexure joints, and epoxy glue. Actuation is carried out by two banks of in-plane electrothermal actuators, one coupled through an out of plane compliant socket, and the other one coupled remotely using a 30 μm diameter Cu wire. In this paper we present the microrobot kinematic design, and experimental identification of the robot Jacobian. Preliminary experimental characterization of the microrobot shows that it is repeatable to less than 0.5 μm along XY axes and 0.015 degrees along Pitch and Yaw DOFs. Finally, the robot was configured to carry an AFM tip and we demonstrate nano indentation sequences on a Parylene substrate.

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Articulated Four Axis Microrobot

Volume 6: ASME Power Transmission and Gearing Conference; 3rd International Conference on Micro- and Nanosystems; 11th International Conference on Advanced Vehicle and Tire Technologies ◽

10.1115/detc2009-87544 ◽

2009 ◽

Author(s):

Rakesh Murthy ◽

Aditya N. Das

Keyword(s):

Degrees Of Freedom ◽

Atomic Force Microscope Probe ◽

Top Down ◽

Deep Reactive Ion Etching ◽

Atomic Force ◽

Work Volume ◽

Out Of Plane ◽

Flexure Joints ◽

End Effectors ◽

Microscope Probe

The picture shows a unique MEMS robot. It is highly dextrous with our degrees of freedom (two in-plane and two out-of-plane) and has the largest work volume of 50μm × 50μm × 75 μm amongst MEMS based positioners. The robot incorporates novel cable based transmission systems to couple in-plane actuators with out of plane bi-directional flexure joints. Constructed out of Deep Reactive Ion Etching and microassembly, this robot is designed to transmit upto 200mN of force along all four axes, precise to ten’s of nanometers and configured to carry a variety of end-effectors such as Atomic Force Microscope probe tip arrays and microgrippers. The microrobot presents the dawn of next generation in top down manipulation systems.

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Sensitivity and Directivity Analysis of Piezoelectric Ultrasonic Cantilever-Based MEMS Hydrophone for Underwater Applications

Journal of Marine Science and Engineering ◽

10.3390/jmse8100784 ◽

2020 ◽

Vol 8 (10) ◽

pp. 784

Author(s):

Basit Abdul ◽

Vincenzo Mariano Mastronardi ◽

Antonio Qualtieri ◽

Luciana Algieri ◽

Francesco Guido ◽

...

Keyword(s):

Thin Film ◽

Stress Gradient ◽

Thin Layers ◽

Functional Layer ◽

Micro Electro Mechanical Systems ◽

Conformal Coating ◽

Out Of Plane ◽

Piezoelectric Cantilevers ◽

Cantilever Bending

In this paper, we report on the characterization of the sensitivity and the directionality of a novel ultrasonic hydrophone fabricated by micro-electro-mechanical systems (MEMS) process, using aluminum nitride (AlN) thin film as piezoelectric functional layer and exploiting a stress-driven design. Hydrophone structure and fabrication consist of four piezoelectric cantilevers in cross configuration, whose first resonant frequency mode in water is designed between 20 kHz and 200 kHz. The MEMS fabricated structures exploit 1 µm and 2 µm thick piezoelectric AlN thin film embedded between two molybdenum electrodes grown by DC magnetron sputtering on silicon (Si) wafer. The 200 nm thick molybdenum electrodes thin layers add a stress-gradient through cantilever thickness, leading to an out-of-plane cantilever bending. A water resistant parylene conformal coating of 1 µm was deposited on each cantilever for waterproof operation. AlN upward bent cantilevers show maximum sensitivity up to −163 dB. The cross configuration of four stress-driven piezoelectric cantilevers, combined with an opportune algorithm for processing all data sensors, permits a finer directionality response of this hydrophone.

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Structurally stitched NCF CFRP laminates. Part 1: Experimental characterization of in-plane and out-of-plane properties

Composites Science and Technology ◽

10.1016/j.compscitech.2010.11.012 ◽

2011 ◽

Vol 71 (5) ◽

pp. 549-568 ◽

Cited By ~ 33

Author(s):

H. Heß ◽

N. Himmel

Keyword(s):

Experimental Characterization ◽

Cfrp Laminates ◽

Out Of Plane

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Experimental characterization of the out-of-plane performance of regular stone masonry walls, including test setups and axial load influence

Bulletin of Earthquake Engineering ◽

10.1007/s10518-015-9742-1 ◽

2015 ◽

Vol 13 (9) ◽

pp. 2667-2692 ◽

Cited By ~ 15

Author(s):

Tiago Miguel Ferreira ◽

Alexandre A. Costa ◽

António Arêde ◽

Ana Gomes ◽

Aníbal Costa

Keyword(s):

Axial Load ◽

Stone Masonry ◽

Masonry Walls ◽

Experimental Characterization ◽

Out Of Plane

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Experimental characterization of the out-of-plane behaviour of masonry infill walls made of lightweight concrete blocks

Engineering Structures ◽

10.1016/j.engstruct.2021.112755 ◽

2021 ◽

Vol 244 ◽

pp. 112755

Author(s):

Marta Agante ◽

André Furtado ◽

Hugo Rodrigues ◽

António Arêde ◽

Paulo Fernandes ◽

...

Keyword(s):

Lightweight Concrete ◽

Experimental Characterization ◽

Infill Walls ◽

Masonry Infill ◽

Masonry Infill Walls ◽

Out Of Plane ◽

Concrete Blocks

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An experimental characterization of wrinkling generated during prepreg autoclave manufacturing using caul plates

Journal of Composite Materials ◽

10.1177/0021998319846556 ◽

2019 ◽

Vol 53 (26-27) ◽

pp. 3757-3773 ◽

Cited By ~ 1

Author(s):

Tobias A Weber ◽

Markus Englhard ◽

Jan-Christoph Arent ◽

Joachim Hausmann

Keyword(s):

Experimental Characterization ◽

Part Geometry ◽

Quality Issue ◽

Out Of Plane ◽

Set Up ◽

Wrinkle Generation ◽

The Given ◽

Part Thickness ◽

Insight Into

Out-of-plane ply wrinkling is a major quality issue for carbon fiber reinforced prepreg parts. Its triggers are numerous and not every influencing parameter is fully understood, yet. The research presented in this paper aims at providing a better insight into ply wrinkling generated during autoclave compaction using caul plates. A detailed description of the experimental set-up and the applied methodology is provided. Statistical analyses of varying influencing factors such as part thickness, geometry, tool–part interaction, and laminate lay-up are presented. This, in turn, generates a better understanding of their impact on fiber wrinkling risk and size. Part geometry and compaction deformation show the most significant influence on wrinkle size. However, for the given manufacturing concept, tool–part interaction also plays a significant role. It influences both the dimension and location of the wrinkles, as well as the existence and size of a critical flange length of the part. A noteworthy effect on wrinkle generation and size can also be observed when adding unidirectional plies to an otherwise fabric laminate.

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Experimental Characterization of the In-plane and Out-of-Plane Behaviour of Infill Masonry Walls

Procedia Engineering ◽

10.1016/j.proeng.2015.08.041 ◽

2015 ◽

Vol 114 ◽

pp. 862-869 ◽

Cited By ~ 3

Author(s):

André Furtado ◽

Hugo Rodrigues ◽

António Arêde ◽

Humberto Varum

Keyword(s):

Masonry Walls ◽

Experimental Characterization ◽

Out Of Plane ◽

Infill Masonry

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An application of CaTraSys, a cable-based parallel measuring system for an experimental characterization of human walking

Robotica ◽

10.1017/s0263574709005645 ◽

2009 ◽

Vol 28 (1) ◽

pp. 119-133 ◽

Cited By ~ 17

Author(s):

Erika Ottaviano ◽

Marco Ceccarelli ◽

Francesco Palmucci

Keyword(s):

Parallel Manipulator ◽

Tracking System ◽

Experimental Results ◽

Measuring System ◽

Human Walking ◽

Experimental Characterization ◽

Experimental Identification ◽

Human Limb

SUMMARYIn this paper, an application is presented of a cable-based parallel manipulator as measuring system for an experimental identification of human walking characteristics. Experimental results have been obtained by means of a new version of CaTraSys (Cassino Tracking System), which is a measuring system that has been designed and built at Laboratory of Robotics and Mechatronics (LARM) in Cassino, Italy. The new version of the CaTraSys system has been used to determine the trajectory of the human limb extremity during walking operation and furthermore the system is able to measure forces that are exerted by a limb. Experimental determination of articulation mobility is also presented with numerical and experimental results.

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Modelling the effect of gaps and overlaps in automated fibre placement (AFP)-manufactured laminates

Science and Engineering of Composite Materials ◽

10.1515/secm-2013-0322 ◽

2015 ◽

Vol 22 (2) ◽

pp. 115-129 ◽

Cited By ~ 19

Author(s):

Xiangqian Li ◽

Stephen R. Hallett ◽

Michael R. Wisnom

Keyword(s):

Finite Element Modelling ◽

Experimental Characterization ◽

Cohesive Elements ◽

Relevant Research ◽

Fibre Direction ◽

Element Modelling ◽

Out Of Plane ◽

Thickness Variations ◽

3D Meshing

AbstractIn automated fibre placement (AFP) process, gaps and overlaps parallel to the fibre direction can be introduced between the adjoining tapes. These gaps and overlaps can cause a reduction in strength compared with pristine conditions. Finite element modelling is an effective way to understand how the size and distribution of such gaps and overlaps influences the strength and failure development. Many modelling work showed that out-of-plane waviness and ply thickness variations caused by gaps and overlaps play an important role in inducing the strength knock-down; however, there has been a lack of effective way to explicitly model the ply waviness, which constrained the relevant research. In this work, 3D meshing tools were developed to automatically generate ply-by-ply models with gaps and overlaps. Intra-ply and inter-ply cohesive elements are also automatically inserted in the model to capture the influence of splitting and delamination. Out-of-plane waviness and ply thickness variations caused by gaps and overlaps are automatically modelled. Models with various sizes and distribution of gaps and overlaps were built to predict the reduction of strength as a function of the magnitude and type of the defects. Results of gap and overlap models will be used to guide future experimental characterization of simulated AFP process defects, manufactured by hand layup from pre-preg tape.

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