The rapid development of very-large format infrared detector arrays has challenged the IR scene projector community
to also develop larger-format infrared emitter arrays to support the testing of systems incorporating these detectors.
In addition to larger formats, many scene projector users require much higher simulated temperatures than can be
generated with current technology in order to fully evaluate the performance of their systems and associated processing
algorithms.
Under the Ultra High Temperature (UHT) development program, Santa Barbara Infrared Inc. (SBIR) is developing a
new infrared scene projector architecture capable of producing both very large format (>1024 x 1024) resistive emitter
arrays and improved emitter pixel technology capable of simulating very high apparent temperatures. During earlier
phases of the program, SBIR demonstrated materials with MWIR apparent temperatures in excess of 1400 K. New
emitter materials have subsequently been selected to produce pixels that achieve even higher apparent temperatures.
Test results from pixels fabricated using the new material set will be presented and discussed. A 'scalable' Read In
Integrated Circuit (RIIC) is also being developed under the same UHT program to drive the high temperature pixels.
This RIIC will utilize through-silicon via (TSV) and Quilt Packaging (QP) technologies to allow seamless tiling of
multiple chips to fabricate very large arrays, and thus overcome the yield limitations inherent in large-scale integrated
circuits. Results of design verification testing of the completed RIIC will be presented and discussed.
The rapid development of very-large format infrared detector arrays has challenged the IR scene projector community to develop correspondingly larger-format infrared emitter arrays to support the testing needs of systems incorporating these detectors. As with most integrated circuits, fabrication yields for the read-in integrated circuit (RIIC) that drives the emitter pixel array are expected to drop dramatically with increasing size, making monolithic RIICs larger than the current 1024x1024 format impractical and unaffordable. Additionally, many scene projector users require much higher simulated temperatures than current technology can generate to fully evaluate the performance of their systems and associated processing algorithms. Under the Ultra High Temperature (UHT) development program, Santa Barbara Infrared Inc. (SBIR) is developing a new infrared scene projector architecture capable of producing both very large format (>1024x1024) resistive emitter arrays and improved emitter pixel technology capable of simulating very high apparent temperatures. During an earlier phase of the program, SBIR demonstrated materials with MWIR apparent temperatures in excess of 1000K. New emitter materials have subsequently been selected to produce pixels that achieve even higher apparent temperatures. Test results from pixels fabricated using the new material set will be presented and discussed. Also in development under the same UHT program is a 'scalable' RIIC that will be used to drive the high temperature pixels. This RIIC will utilize through-silicon vias (TSVs) and quilt packaging (QP) technologies to allow seamless tiling of multiple chips to fabricate very large arrays, and thus overcome the inherent yield limitations of very-large-scale integrated circuits. Current status of the RIIC development effort will also be presented.
High pixel temperatures for IR scene projector arrays face materials challenges of oxidation, diffusion, and recrystallization. For cost effective development of new high-temperature materials, we have designed and fabricated simplified pixels for testing. These consist of resistive elements, traces, and bond pads sandwiched between dielectric layers on Si wafers. Processing involves a pad exposure etch, a pixel outline etch, and an undercut etch to thermally isolate the resistive element from the substrate. Test pixels were successfully fabricated by electron-beam lithography using a combination of wet and dry etching.
To meet the needs of high fidelity infrared sensors, under the Ultra High Temperature (UHT) development program, Santa Barbara Infrared Inc. (SBIR) has developed new infrared emitter materials capable of achieving extremely high temperatures. The current state of the art arrays based on the MIRAGE-XL generation of scene projectors is capable of producing imagery with mid-wave infrared (MWIR) apparent temperatures up to 700K with response times of 5 ms. The Test Resource Management Center (TRMC) Test and Evaluation/Science and Technology (TandE/SandT) Program through the U.S. Army Program Executive Office for Simulation, Training and Instrumentations (PEO STRI) has contracted with SBIR and its partners to develop a new resistive array based on these new materials, using a high current Read-In Integrated Circuit (RIIC) capable of achieving higher temperatures as well as faster frame rates. The status of that development will be detailed within this paper, including performance data from prototype pixels.
Several new technologies have been developed over recent years that make a fundamental change in the scene projection for infrared hardware in the loop test. Namely many of the innovations are in Read In Integrated Circuit (RIIC) architecture, which can lead to an operational and cost effective solution for producing large emitter arrays based on the assembly of smaller sub-arrays. Array sizes of 2048x2048 and larger are required to meet the high fidelity test needs of today’s modern infrared sensors. The Test Resource Management Center (TRMC) Test and Evaluation/Science and Technology (T and E/S and T) Program through the U.S. Army Program Executive Office for Simulation, Training and Instrumentations (PEO STRI) has contracted with SBIR and its partners to investigate integrating new technologies in order to achieve array sizes much larger than are available today. SBIR and its partners have undertaken several proof-of-concept experiments that provide the groundwork for producing a tiled emitter array. Herein we will report on the results of these experiments, including the demonstration of edge connections formed between different ICs with a gap of less than 10µm.
The Ultra High Temperature (UHT) development program will develop, package, and deliver high temperature scene
projectors for the U.S. Government. The Infrared Scene Projector (IRSP) systems goals are to be capable of extremely
high temperatures, in excess of 2000K, as well as fast frame rates, 500 Hz, and 2 ms rise times. The current status of the
pixel design will be discussed with an emphasis on the models developed to facilitate these designs and estimate
performance prior to fabrication.
The use of coded apertures in a large area MWIR system introduces a number of difficulties including the effects of
diffraction and other distortions not observed in shorter wavelength systems. A new approach is being developed that
addresses the effects of diffraction while gaining the benefits of coded apertures, thus providing the flexibility to vary
resolution, possess sufficient light gathering power, and achieve a wide field of view (WFOV). The photonic MEMS
artificial eyelid array technology is currently being applied as the coded aperture in this program for surveillance
enabling technology development. Speed, lifetime, packaging and scalability are all critical factors for the MEMS eyelid
technology to determine system efficacy as well as military and commercial usefulness. The electronic eyelid is the
fundamental addressable unit for adaptive code generation and will allow the system to multiplex in time for increased
resolution. The proposed system consists of four subsystems in parallel with each subsystem consisting of four subapertures.
Each sub-aperture contains an artificial eyelid array capable of 36 different, independent patterns of open
500µm eyelids corresponding to 36 different look directions. Dynamic aperture arrays were fabricated on both quartz
and sapphire substrates for operation in the visible to MWIR. Both 8x8 and 40x40 element arrays were designed,
fabricated, and tested with the capability of 4, 8, and 16 unique pattern combinations. Process and device improvements
have been implemented to improve the yield of the MEMS arrays. In addition to mechanical evaluations, the eyelid
arrays were tested optically to demonstrate the capability of multiple look directions.
Extension of coded apertures to the MWIR introduces the effects of diffraction and other distortions not observed in
shorter wavelength systems. A new approach is being developed under the DARPA/SPO funded LACOSTE (Large
Area Coverage Optical search-while Track and Engage) program, that addresses the effects of diffraction while gaining
the benefits of coded apertures, thus providing flexibility to vary resolution, possess sufficient light gathering power, and
achieve a wide field of view (WFOV). The photonic MEMS "eyelid" array technology is currently being instantiated in
this DARPA Surveillance program study as the "heart", mediating the flow of the incoming signal. However, speed,
lifetime, packaging and scalability are critical factors for the MEMS "eyelid" technology which will determine system
efficacy as well as military and commercial usefulness. The electronic eyelid array is the fundamental addressable unit
for adaptive code generation and will allow the system to multiplex in time for increased resolution. The binary code
which determines whether a 500μm eyelid is open or closed is referred to as the "eyelid code." Groups of eyelids can
work together as a "super aperture" by virtue of a "macro-code." A macro code becomes relevant to describe how
dispersed eyelids across the 0.19m x 0.19m aperture will function together. Dynamic aperture arrays were fabricated on
both quartz and sapphire substrates for operation in the visible to MWIR. Both 8x8 and 40x40 element arrays were
designed, fabricated, and tested with macro-codes consisting of 4, 8, and 16 unique combinations. The die were
packaged and tested in ambient for robust eyelid operations. The point spread function was also measured in an optical
setup with the eyelid arrays located in the aperture plane.
KEYWORDS: Cryogenics, Analog electronics, Electronics, Prototyping, Packaging, Interfaces, Mid-IR, Digital electronics, Microelectromechanical systems, Temperature metrology
SBIR has completed the development of the first lot of OASIS emitter arrays and custom packaging for cryogenic IR scene projection applications. OASIS performance requirements include a maximum MWIR apparent temperature of greater than 600 K, with 10-90% radiance rise time of less than 6.5 ms. Four (4) arrays have been packaged, integrated, tested and delivered.
This paper will report on the first measurements taken of the OASIS resistive emitter arrays at both ambient and cryogenic temperatures. This paper will also provide a discussion of the OASIS cryogenic projector/electronics module (Cryo-PEM) design. We will also describe the novel thermal design employed within the array package and Cryo-PEM assemblies, which allows OASIS to produce radiometrically accurate imagery with reduced thermal lag/gradient artifacts compared to legacy Honeywell cryogenic IRSP assemblies. As OASIS supports both analog and digital input, we will discuss the differences between the two modes in terms of system integration, support electronics and overall array performance.
SBIR has passed the midpoint of delivering ten 1024x1024 IR Scene Projector Systems (IRSPs) to the Government. Six systems have been installed at Redstone Technical Test Center (RTTC), Patuxent River, and Edwards Air Force Base. Four more systems are in production and will be shipped by the end of this year. The commercial name of the LFRA IRSP is Mirage XL. This ground breaking projector technology is being leveraged on the Wide Format Resistive Array (WFRA) program and on the Mirage II product. The WFRA IRSP, also known as Mirage HD, features an even larger 1536x768 emitter array and will be in system integration by the end of the year. Mirage II, which also leverages LFRA, is being readied as the next generation 512x512 projector system.
Additional signal processing capabilities have been installed in the LFRA systems. Each system now has full Translation/Rotation Processing (TRP) capability. Systems also have image convolution and 400Hz 1024x512 windowing capabilities.
SBIR has completed design and development of prototype emitter arrays and is completing custom cryogenic vacuum device packaging and support electronics for the Optimized Arrays for Space-background Infrared Simulation (OASIS) program. The OASIS array is a 512 x 512 device featuring high output dynamic range, a selectable analog/digital scene data interface, and the capability to operate from cryogenic to ambient substrate temperatures - thereby providing an enabling technology for projection of simulated radiance of space-background scenes. Prototype emitter production has been completed at RTI International in support of initial deliveries. The OASIS array package incorporates novel electrical bussing schemes optimized for the OASIS RIIC and a modular architecture to allow user re-configuration of both window and emitter shield. The OASIS package leverages LFRA operation features, and supports both ambient and cryogenic chamber-based operation with a minimum of mechanical and electrical re-configuration. The OASIS close support electronics (CSE) supports both analog and digital input data modes, while providing easy electronic connection between arrays installed in the cryogenic chamber and the external control and scene-generation systems. We present a technical overview of the OASIS array/package and CSE designs, and will report on measured radiometric performance from prototype OASIS arrays.
SBIR has completed development of the Large Format Resistive Array (LFRA) Infrared Scene Projector (IRSP) and shipped the first production system. Nine more systems are in production and will be shipped to several US Government customers on approximately six week centers. The commercial name of the LFRA IRSP is Mirage XL. System performance meets a broad range of program requirements and SBIR has been extremely successful in producing this ground breaking projector. Tests performed on System #1 reveal broad compliance to the specification and, in particular, outstanding emitter array performance. Key emitter requirements that have been met or exceeded include Operability, Maximum Apparent Temperature, and Array Uniformity. Key System specifications are:
Large-format emitter array (1024x1024);
High maximum apparent temperature (>700K);
200 Hz full-frame operation;
400 Hz static window mode (1024x512);
Non Uniformity (uncorrected) <10%.
SBIR's family of MIRAGE infrared scene projection systems is undergoing significant growth and expansion. The first two lots of production IR emitters have completed fabrication at Microelectronics Center of North Carolina/Research and Development Institute (MCNC-RDI), and the next round(s) of emitter production has begun. These latest emitter arrays support programs such as Large Format Resistive Array (LFRA), Optimized Array for Space-based Infrared Simulation (OASIS), MIRAGE 1.5, and MIRAGE II. We present the latest performance data on emitters fabricated at MCNC-RDI, plus integrated system performance on recently completed IRSP systems. Teamed with FLIR Systems/Indigo Operations, SBIR and the Tri-Services IRSP Working Group have completed development of the CMOS Read-In Integrated Circuit (RIIC) portion of the Wide Format Resistive Array (WFRA) program-to extend LFRA performance to a 768 x 1536 "wide screen" projection configuration. WFRA RIIC architecture and performance is presented. Finally, we summarize development of the LFRA Digital Emitter Engine (DEE) and OASIS cryogenic package assemblies, the next-generation Command & Control Electronics (C&CE).
An electrostatic MEMS actuator is described for use as an analog micromirror device (AMD) for high performance, broadband, hardware-in-the-loop (HWIL) scene generation. Current state-of-the-art technology is based on resistively heated pixel arrays. As these arrays drive to the higher scene temperatures required by missile defense scenarios, the power required to drive the large format resistive arrays will ultimately become prohibitive. Existing digital micromirrors (DMD) are, in principle, capable of generating the required scene irradiances, but suffer from limited dynamic range, resolution and flicker effects. An AMD would be free of these limitations, and so represents a viable alternative for high performance UV/VIS/IR scene generation. An electrostatic flexible film actuator technology, developed for use as "artificial eyelid" shutters for focal plane sensors to protect against damaging radiation, is suitable as an AMD for analog control of projection irradiance. In shutter applications, the artificial eyelid actuator contained radius of curvature as low as 25um and operated at high voltage (>200V). Recent testing suggests that these devices are capable of analog operation as reflective microcantilever mirrors appropriate for scene projector systems. In this case, the device would possess larger radius and operate at lower voltages (20-50V). Additionally, frame rates have been measured at greater than 5kHz for continuous operation. The paper will describe the artificial eyelid technology, preliminary measurements of analog test pixels, and design aspects related to application for scene projection systems. We believe this technology will enable AMD projectors with at least 5122 spatial resolution, non-temporally-modulated output, and pixel response times of <1.25ms.
Santa Barbara Infrared's (SBIR) family of MIRAGE infrared scene projection systems is undergoing significant growth and expansion. The first lot of production IR emitters is in fabrication at Microelectronics Center of North Carolina/Research and Development Institute (MCNC-RDI), the state-of-the-art MEMS foundry and R&D center which completed prototype fabrication in early 2003. The latest emitter arrays are being produced in support of programs such as Large Format Resistive Array (LFRA) and MIRAGE 1.5, MIRAGE II, and OASIS. The goal of these new development programs is to increase maximum scene temperature, decrease radiance rise time, support cryogenic operation, and improve operability and yield. After having completed an extremely successful prototype run in 2003, SBIR and MCNC-RDI have implemented a variety of emitter process improvements aimed at maximizing performance and process yield. SBIR has also completed development and integration of the next-generation MIRAGE command and control electronics (C&CE), an upgraded calibration radiometry system (CRS), and has developed test equipment and facilities for use in MIRAGE device wafer probing, test, evaluation, diagnostic, and assembly processes. We present the latest emitter performance data, an overview of emitter foundry processing and packaging improvements, and an update on MIRAGE II, LFRA, and OASIS development programs.
In this paper we develop a mathematical model to simulate the actuation of a multilayer metallic strip. In the first step of the model development, we employ previous theory to quantify the radius of curvature in the unimorph due to differing thermal coefficients in the constituent materials. The resulting radius of curvature is subsequently used to compute the voltage required to uncurl the actuator. Numerical experiments were performed with the model and the trends were found to be in agreement with experimental data.
An electrostatic MEMS actuator known as the “Artificial Eyelid” can be used as a micromechanical chopper for IR detectors. The actuator structure consists of a curled polymer/metal film stack which is microfabricated and released from an IR transparent substrate. The film stack is uncurled by applying an electric field between the curled film and the transparent fixed electrode on the substrate. These flexible film actuators can act as IR choppers, providing transmission of radiation to the sensor elements when open (curled) and reflection when closed (uncurled). Arrays of actuators were fabricated on ITO-coated glass substrates and ranged in size from 4 x 4 mm to 7.5 x 15 mm with individual elements ranging from 250 to 500 μm on a side. Actuation for devices with average radius of curvature of 120 μ was consistently achieved at 150-170 V operation with 98-100% of the elements functioning and long lifetimes. IR chopper characteristics were measured using a blackbody source and pyroelectric detector by applying sine and square wave voltage to the actuators at a frequency of 30 Hz. The capability of the artificial eyelid for chopping near- and mid-IR radiation, including future fabrication of devices using NiCo2O4 or NiRh2O4 films for IR transparent electrodes, will be discussed.
SBIR's family of MIRAGE infrared scene projection systems is undergoing significant growth and expansion. SBIR has completed the transition of Honeywell's resistive emitter technology to MCNC Research and Development Institute (MCNC-RDI), and is preparing for first-lot production of IR emitters in support of ongoing programs. Development of MIRAGE resistive emitter-based products is underway in order to increase maximum scene temperature, decrease radiance rise time, and improve overall operation. The 1024 x 1024 Large Format Resistive Array (LFRA) Read-In Integrated Circuit (RIIC) has been fabricated and tested, with emitter fabrication to start in mid-2003. A next-generation MIRAGE II(512 x 512) RIIC is also ready for fabrication, in support of high-performance MIRAGE II 512 x 512 systems providing greater than 750 K MWIR apparent temperature, and less than 5 ms 10-90% MWIR radiance rise time. In support of these new technologies and products, SBIR has developed test equipment and facilities for use in next-generation MIRAGE device wafer probing, test, evaluation, diagnostic, and assembly processes.
An electrostatic MEMS actuator, known as the "Artificial Eyelid," can be used as a micromechanical chopper for uncooled IR detectors such as pyroelectrics and microbolometers. These flexible film actuators act as tightly curled shutters, providing transmission of IR radiation to the sensor elements when open and reflection of the IR when closed. The actuator structure consists of a curled polymer/metal film stack which is microfabricated and released from an IR transparent substrate. The film stack is uncurled by applying an electric field between the curled film and the transparent fixed electrode on the substrate. Devices produced to date have ranged in size from 50 microns to 2 mm on a side and can be fabricated in array form to chop the IR signal for a FPA. Recently, 4 x 4 mm arrays with actuator elements ranging in size from 250 x 600 microns to 600 x 1000 microns have been fabricated with 95-100% of the elements functioning at 150-280 V. Current status of the development of these actuators and testing of micromechanical chopper arrays will be discussed.
The fabrication, testing and performance of a new device for the protection of optical sensors will be described. The device consists of a transparent substrate, a transparent conducting electrode, insulating polymers, and a reflective top electrode layer. Using standard fabrication techniques, arrays of apertures can be created with sizes ranging from micrometers to millimeters. A stress gradient resulting from different coefficients of thermal expansion between the top polymer layer and the reflective metal electrode, rolls back the composite thin film structure from the aperture area following the chemical removal of a release layer, thus forming the open condition. The application of a voltage between the transparent conducting and reflective metal electrodes creates an electrostatic force that unrolls the curled film, closing the artificial eyelid. Fabricated devices have been completed on glass substrates with indium tin oxide electrodes. The curled films have diameters of less than 100micrometers with the arrays having fill factor transparencies of over 70%. Greater transparencies are possible with optimized designs. The electrical and optical results from the testing of the artificial eyelid will be discussed.
Flexible film electrostatic MEMS actuators can be used as micromachined IR choppers for pyroelectric and microbolometer sensors. The flexible actuators act as tightly curled shutters, providing transmission of IR radiation to the sensor elements when open and reflection of the IR when closed. These actuators consist of a polymer/metal film stack which is microfabricated and released from a substrate. Thermal and mechanical stress in the film stack causes the actuator to curl when released, and the film can be uncurled by applying an electric field between the curled film and the substrate. Tightly curled actuators in the range of 50 μm to 1 mm square have been fabricated, and arrays have been produced and operated. Operating voltage is in the range of 50 - 300 V with frequencies > 5 kHz. The performance of these actuators is presented, and their applicability to IR choppers is discussed.
The Integrated Force Array (IFA) is a metallized polyimide actuator made up of a large array of capacitive cells that deform when voltage is applied. The deformations of the individual cells add to produce an overall muscle-like compression of the array. In previously reported work deformations of up to 30% have been realized and the IFAs have been used as mechanical scanners in ultrasound imaging systems. The gaps of the capacitive cells are etched directly into the polyimide and oriented perpendicular to the plane of the array. Metal is deposited on the sidewalls of the etched features in order to form the plates of each capacitor. The force associated with the IFA motion is directly proportional to the height of the sidewall metal and thus to the thickness of the membrane. Until now, the thickness has been 2μm with gap widths of 1μm. In recent work, much higher aspect ratio IFAs (thicker but with the same gap width) have been fabricated in order to produce devices that operate with greater force and are much more robust devices.
The fabrication, testing and performance of a new device for the protection of optical sensors will be described. The device consists of a transparent substrate, a transparent conducting electrode, insulating polymers, and a reflective top electrode layer. Using standard integrated circuit fabrication techniques, arrays of apertures can be created with sizes ranging from micrometers to millimeters. A stress gradient resulting from different thermal coefficients of expansion between the top polymer layer and the reflective metal electrode, rolls back the composite thin film structure from the aperture area once a release layer is chemically etched away, forming a tightly curled film at one side of the aperture - the open condition. The application of a voltage between the transparent conducting and reflective metal electrodes creates an electrostatic force which unrolls the curled film, closing the artificial eyelid. Fabricated devices have been completed on glass substrates with indium tin oxide electrodes. The curled films have diameters of less than 100micrometers with the arrays having mechanical transparencies of over 80%. Greater transparencies are possible with optimized designs. The electrical and optical results from the testing of the artificial eyelid will be discussed including the optimization of the design and fabrication for applications in systems that extend into the IR spectrum. A primary area of investigation is the choice of the transparent conducting electrode.
A novel concept for protection of optical sensor will be described. The device consist of a transparent substrate, a transparent conducting electrode, insulating polymers, and a reflective top electrode layer. Using thin film deposition and photolithographic fabrication techniques commonly available for manufacture of integrated circuits, plus spin coating as commonly used for polymers, the layers can be placed on the substrate and arrays of apertures created with sizes ranging from micrometers to millimeters. Due to the stress gradient between the polymer dielectric and the reflective metal electrodes, the composite thin film structure will open over the aperture area once a 'release layer' is removed by chemical treatment. This is the 'open' condition for the 'eyelid'. By applying a voltage between the transparent conducting the metal electrodes, an electrostatic force is created which closes the 'eyelid'. Upon elimination of the voltage, the stress gradient opens the 'eyelid' again. Preliminary devices have been fabricated and operated up to a frequency of 4kHz and at lifetimes of over 1010 cycles. The power consumption is extremely low. The potential of this technology for a variety of applications will be discussed.
A miniature ultrasound scanner has been constructed using a MEMS actuator called an Integrated Force Array. A second type of actuator called a Spiral Wound Transducer (SWT) is under development and shows significant promise for this application. Both the scanner and SWT will be discussed.
Integrated Force Arrays (IFAs) are thin film linear actuators which operate with substantial displacement and force. The methods of attachment of these devices to external systems are under development. Our current methods to incorporate IFAs in an scanning ultrasound imaging systems as well as a new material and method for attachment will be described.
Stephen Bobbio, Scott Goodwin-Johansson, Thomas DuBois, Farid Tranjan, Stephen Smith, Richard Fair, Christian Ball, James Jacobson, Charles Bartlett, Nadeem Eleyan, Hussein Makki, R. Gupta
Integrated Force Arrays (IFAs) are thin film membrane actuators that act as transfer devices for electrostatic force. They are capable of large amplitude motion and evidence significant energies per unit volume (eg. 8.2 erg/mm3). Devices which use IFAs as drivers to scan PZT acoustic imaging transducers are under development and will be discussed here.
Scott Goodwin-Johansson, Stephen Bobbio, Charles Bartlett, Nadeem Eleyan, James Jacobson, Joseph Mancusi, Lindsey Yadon, Christian Ball, Thomas DuBois, William Palmer, David Vellenga, Farid Tranjan
IFAs are MEMS actuators which are powered by the electrostatic forces between the plates of many microscopic deformable capacitors arranged in monolithic arrays. IFAs are fabricated using standard techniques of VLSI electronics. The IFAs reported here resemble thin, flexible plastic membranes 10 mm long and either 1 or 3 mm wide, which contain from 75,000 to 200,000 cells. They are low-weight, high-efficiency actuators with low power consumption, silent operation, and absence of sliding friction. Testing methods applicable to these free- standing MEMS structures are discussed, along with experimental observations and measurements of forces and displacements. We have measured forces in excess of 6 dynes and displacements of over 700 micrometers . The force/cross-sectional area of this MEMS structure is 2800 dynes/mm2, and the work done by the IFA divided by its volume is in excess of 7 ergs/mm3. A rate over 20,000 contractions/second has been observed, as well as lifetimes of greater than 108 contractions. The metalization of the IFA strongly affects the performance. Experimental results are presented demonstrating the improvements in the performance with a Cr/Au metal system compared to the Cr/Pd metal system originally used.
Integrated Force Arrays (IFAs) are thin, flexible, metallized membranes which may be configured as actuators or sensors. The current prototype structures are approximately 1 cm long by 1 mm wide and designed for deformations of 2 mm. In this paper we will discuss how the devices may be scaled-up for extended range and force.
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