MEMS for In Situ Testing—Handling, Actuation, Loading, and Displacement Measurements

MRS Bulletin ◽  
2010 ◽  
Vol 35 (5) ◽  
pp. 375-381 ◽  
Author(s):  
M.A. Haque ◽  
H.D. Espinosa ◽  
H.J. Lee
Keyword(s):  
Microelectromechanical Systems ◽  
Specimen Preparation ◽  
Mems Devices ◽  
Sensors And Actuators ◽  
Friction Testing ◽  
Simultaneous Acquisition ◽  
Natural Choice ◽  
Analytical Tools ◽  
Materials Behavior

AbstractMechanical testing of micro- and nanoscale materials is challenging due to the intricate nature of specimen preparation and handling and the required load and displacement resolution. In addition, in Situ testing requires the entire experimental setup to be drastically miniaturized, because conventional high-resolution microscopes or analytical tools usually have very small chambers. These challenges are increasingly being addressed using microelectromechanical systems (MEMS)-based sensors and actuators. Because of their very small size, MEMS-based experimental setups are the natural choice for materials characterization under virtually all forms of in Situ electron, optical, and probe microscopy. The unique advantage of such in Situ studies is the simultaneous acquisition of qualitative (up to near atomic visualization of microstructures and deformation mechanisms) and quantitative (load, displacement, flaw size) information of fundamental materials behavior. In this article, we provide a state-of-the-art overview of design and fabrication of MEMS-based devices for nanomechanical testing. We also provide a few case studies on thin films, nanowires, and nanotubes, as well as adhesion-friction testing with a focus on in Situ microscopy. We conclude that MEMS devices offer superior choices in handling, actuation, and force and displacement resolutions. Particularly, their tight tolerances and small footprints are difficult to match by off-the-shelf techniques.

Microsensors, MEMS and NEMS Based Complex Adaptive Smart Devices and Systems

2001 ◽  
Author(s):  
Vijay K. Varadan
Keyword(s):  
Self Assembly ◽  
Communication Systems ◽  
Microelectromechanical Systems ◽  
System Level ◽  
Smart Devices ◽  
Mems Devices ◽  
Wafer Level ◽  
Sensors And Actuators ◽  
Complex Adaptive ◽  
Microelectronics Industry

Abstract The microelectronics industry has seen explosive growth during the last thirty years. Extremely large markets for logic and memory devices have driven the development of new materials, and technologies for the fabrication of even more complex devices with features sizes now down at the sub micron level. Recent interest has arisen in employing these materials, tools and technologies for the fabrication of miniature sensors and actuators and their integration with electronic circuits to produce smart devices and MicroElectroMechanical Systems (MEMS). This effort offers the promise of: 1. Increasing the performance and manufacturability of both sensors and actuators by exploiting new batch fabrication processes developed for the IC and microelectronics industry. Examples include micro stereo lithographic and micro molding techniques. 2. Developing novel classes of materials and mechanical structures not possible previously, such as diamond like carbon, silicon carbide and carbon nanotubes, micro-turbines and micro-engines. 3. Development of technologies for the system level and wafer level integration of micro components at the nanometer precision, such as self-assembly techniques and robotic manipulation. 4. Development of control and communication systems for MEMS devices, such as optical and RF wireless, and power delivery systems.

scholarly journals Effects of Gas Adsorption in Nanotribology and Demonstration of In-Situ Vapor Phase Lubrication of MEMS Devices

2007 ◽  
Author(s):  
David B. Asay ◽  
Michael T. Dugger ◽  
Seong H. Kim
Keyword(s):  
Vapor Phase ◽  
Microelectromechanical Systems ◽  
Silicon Oxide ◽  
Gas Adsorption ◽  
Extended Period ◽  
Adsorbed Water ◽  
Oxide Surface ◽  
Mems Devices ◽  
Vapor Phase Lubrication

This paper discusses the important role of gas adsorption in nanotribology and demonstrates in-situ vapor phase lubrication of microelectromechanical systems (MEMS) devices. We have elucidated the molecular ordering and thickness of the adsorbed water layer on the clean silicon oxide surface and found the molecular-level origin for the high adhesion between nano-asperity silicon oxide contacts in humid ambient. The same gas adsorption process can be utilized for continuous supply of lubricant molecules to form a few Å thick lubricant films on solid surfaces. Using alcohol vapor adsorption, we demonstrated that the adhesion, friction, and wear of the silicon oxide surface can significantly be reduced. This process made it possible to operate sliding MEMS without failure for an extended period of time.

Test Bed for Mechanical Characterization of Nanowires

2005 ◽  
Vol 219 (2) ◽  
pp. 57-65 ◽  
Author(s):  
A. V. Desai ◽  
M. A. Haque
Keyword(s):  
Specimen Preparation ◽  
Length Scale ◽  
Test Bed ◽  
Sensors And Actuators ◽  
Oxide Nanowires ◽  
Superior Mechanical Properties ◽  
Single Nanowires ◽  
Electron Microscopes

Nanowires are one-dimensional solids that are deemed to be the building-block materials for next-generation sensors and actuators. Owing to their unique length scale, they exhibit superior mechanical properties and other length-scale-dependent phenomena. Most of these are challenging to explore, owing to the difficulties in specimen preparation, manipulation, and the requirement of high-resolution force and displacement sensing. To address these issues, a micromechanical device for uniaxial mechanical testing of single nanowires and nanotubes is used here. The device has 10 nN force and 1 nm displacement resolution and its small size (2 ×1 mm) allows for in situ experimentation inside analytical chambers, such as the electron microscopes. A microscale pick-and-place technique is presented as a generic specimen preparation and manipulation method for testing single nanowires. Preliminary results on zinc oxide nanowires show the Young's modulus and fracture strain to be about 76 GPa and 8 per cent respectively.

Integrated MEMS Technologies

MRS Bulletin ◽  
2001 ◽  
Vol 26 (4) ◽  
pp. 291-295 ◽  
Author(s):  
Andrea E. Franke ◽  
Tsu-Jae King ◽  
Roger T. Howe
Keyword(s):  
Microelectromechanical Systems ◽  
Inertial Sensors ◽  
State Of The Art ◽  
Mems Devices ◽  
Sensors And Actuators ◽  
Component Level ◽  
Substantial Impact ◽  
The Past ◽  
Current State ◽  
Mems Technology

While microelectromechanical systems (MEMS) technology has made a substantial impact over the past decade at the device or component level, it has yet to realize the “S” in its acronym, as complex microsystems consisting of sensors and actuators integrated with sense, control, and signal-processing electronics are still beyond the current state of the art. There are several incentives to co-fabricate MEMS devices and electronics on a single silicon chip, which apply to applications such as inertial sensors.

Investigation of Micro-Scale Materials Behavior With MEMS

1999 ◽  
Author(s):  
M. A. Haque ◽  
M. T. A. Saif
Keyword(s):  
Force Measurement ◽  
Mems Devices ◽  
Free Standing ◽  
Comb Drive ◽  
Micro Scale ◽  
Aluminum Specimen ◽  
Tension Testing ◽  
Mems Device ◽  
Materials Behavior

Abstract This study presents a methodology for uniaxial tension testing of both micron and sub-micron scale specimens using MEMS devices. The methodology allows free standing, single or multi-layered specimens to be fabricated separately from the MEMS device. The MEMS device is a comb drive actuator which can be calibrated for force measurement. Materials behavior can be observed in-situ in analytical chambers such as SEM and TEM and under different environmental conditions. The methodology is demonstrated with the testing of a free standing polymer and an Aluminum specimen with thickness 1.3 microns and 110 nanometers respectively. Significant deviation in materials behavior is observed between bulk and micro-scale.

Multi-Physics of Nanoscale Thin Films and Interfaces

2011 ◽  
Author(s):  
M. A. Haque
Keyword(s):  
Thin Films ◽  
Tensile Fracture ◽  
Simultaneous Acquisition ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Mechanical Tensile ◽  
Characterization Of Materials ◽  
Materials Behavior

We present the design and fabrication of a microchip capable of performing mechanical (tensile, fracture, fatigue), electrical (conductivity and band gap) and thermal (conductivity and specific heat) characterization of materials and interfaces. The chip can study thin films and wires of any material that can be deposited on a substrate or study thin coupons if the specimen is in bulk form. The 3 mm × 3 mm size of the chip results in the unique capability of in-situ testing in analytical chambers such as the transmission electron microscope. The basic concept is to ’see’ the micro-mechanisms while ‘measuring’ the deformation and transport properties of materials and interfaces. The advantage of such simultaneous acquisition of quantitative and qualitative data is the accurate and quick physics-based modeling of materials behavior. We present preliminary studies on multi-physics, or the coupling among mechanical thermal and electrical domains in materials will be presented. These results are particularly important when the specimen dimension becomes comparable to the mean free paths of electron and phonons.

In situ TEM studies of irradiation effects for materials improvement

1991 ◽  
Vol 49 ◽  
pp. 452-453
Author(s):  
Charles W. Allen
Keyword(s):  
Nuclear Reactor ◽  
Austenitic Stainless Steels ◽  
High Energy ◽  
Point Of View ◽  
In Situ Tem ◽  
Irradiation Effects ◽  
Tem Analysis ◽  
Radiation Induced ◽  
Analytical Tools

Irradiation effects studies employing TEMs as analytical tools have been conducted for almost as many years as materials people have done TEM, motivated largely by materials needs for nuclear reactor development. Such studies have focussed on the behavior both of nuclear fuels and of materials for other reactor components which are subjected to radiation-induced degradation. Especially in the 1950s and 60s, post-irradiation TEM analysis may have been coupled to in situ (in reactor or in pile) experiments (e.g., irradiation-induced creep experiments of austenitic stainless steels). Although necessary from a technological point of view, such experiments are difficult to instrument (measure strain dynamically, e.g.) and control (temperature, e.g.) and require months or even years to perform in a nuclear reactor or in a spallation neutron source. Consequently, methods were sought for simulation of neutroninduced radiation damage of materials, the simulations employing other forms of radiation; in the case of metals and alloys, high energy electrons and high energy ions.

Investigation of ferroelectrics using conventional and in situ electron microscopy

1994 ◽  
Vol 52 ◽  
pp. 586-587
Author(s):  
V. Saikumar ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Nonvolatile Memory ◽  
Ferroelectric Materials ◽  
Gate Insulator ◽  
Sensors And Actuators ◽  
In Situ Electron Microscopy ◽  
Ferroelectric Domains ◽  
Domain Boundaries ◽  
Domain Interactions ◽  
Memory Applications

In recent years, there has been a growing interest in the application of ferroelectric thin films for nonvolatile memory applications and as a gate insulator in DRAM structures. In addition, bulk ferroelectric materials are also widely used as components in electronic circuits and find numerous applications in sensors and actuators. To a large extent, the performance of ferroelectric materials are governed by the ferroelectric domains (with dimensions in the micron to sub-micron range) and the switching of domains in the presence of an applied field. Conventional TEM studies of ferroelectric domains structures, in conjunction with in-situ studies of the domain interactions can aid in explaining the behavior of ferroelectric materials, while providing some answers to the mechanisms and processes that influence the performance of ferroelectric materials. A few examples from bulk and thin film ferroelectric materials studied using the TEM are discussed below.Figure 1 shows micrographs of ferroelectric domains obtained from undoped and Fe-doped BaTiO3 single crystals. The domain boundaries have been identified as 90° domains with the boundaries parallel to <011>.

Development of Thin Metal Film Deposition Process for the Intravascular Catheter

1999 ◽  
Author(s):  
Seok Chung ◽  
Jun Keun Chang ◽  
Dong Chul Han
Keyword(s):  
Metal Film ◽  
Three Dimensional ◽  
Deposition Process ◽  
Medical Application ◽  
Thin Metal Film ◽  
Film Deposition ◽  
Thin Metal ◽  
Mems Devices ◽  
Sensors And Actuators ◽  
Custom Made

Abstract To make some MF.MS devices such as sensors and actuators be useful in the medical application, it is required to integrate this devices with power or sensor lines and to keep the hole devices biocompatible. Integrating micro machined sensors and actuators with conventional copper lines is incompatible because the thin copper lines are not easy to handle in the mass production. To achieve the compatibility of wiring method between MEMS devices, we developed the thin metal film deposition process that coats micropattered thin copper films on the non silicon-wafer substrate. The process was developed with the custom-made three-dimensional thin film sputter/evaporation system. The system consists of process chamber, two branch chambers, substrate holder unit and linear/rotary motion feedthrough. Thin metal film was deposited on the biocompatible polymer, polyurethane (PellethaneR) and silicone, catheter that is 2 mm in diameter and 1,000 mm in length. We deposited Cr/Cu and Ti/Cu layer and made a comparative study of the deposition processes, sputtering and evaporation. The temperature of both the processes were maintained below 100°C, for the catheter not melting during the processes. To use the films as signal lines connect the signal source to the actuator on the catheter tip, we machined the films into desired patterns with the eximer laser. In this paper, we developed the thin metal film deposition system and processes for the biopolymeric substrate used in the medical MEMS devices.

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