Vision for Micro Technology Space Missions

It is exciting to contemplate the various space mission applications that Micro Electro Mechanical Systems (MEMS) technology could enable in the next 10-20 years. The primary objective of this chapter is to both stimulate ideas for MEMS technology infusion on future NASA space missions and to spur adoption of the MEMS technology in the minds of mission designers. This chapter is also intended to inform non-space oriented MEMS technologists, researchers and decision makers about the rich potential application set that future NASA Science and Exploration missions will provide. The motivation for this chapter is therefore to lead the reader down a path to identify and it is exciting to contemplate the various space mission applications that Micro Electro Mechanical Systems (MEMS) technology could enable in the next 10-20 years. The primary objective of this chapter is to both stimulate ideas for MEMS technology infusion on future NASA space missions and to spur adoption of the MEMS technology in the minds of mission designers. This chapter is also intended to inform non-space oriented MEMS technologists, researchers and decision makers about the rich potential application set that future NASA Science and Exploration missions will provide. The motivation for this chapter is therefore to lead the reader down a path to identify and consider potential long-term, perhaps disruptive or revolutionary, impacts that MEMS technology may have for future civilian space applications. A general discussion of the potential for MEMS in space applications is followed by a brief showcasing of a few selected examples of recent MEMS technology developments for future space missions. Using these recent developments as a point of departure, a vision is then presented of several areas where MEMS technology might eventually be exploited in future Science and Exploration mission applications. Lastly, as a stimulus for future research and development, this chapter summarizes a set of barriers to progress, design challenges and key issues that must be overcome in order for the community to move on, from the current nascent phase of developing and infusing MEMS technology into space missions, in order to achieve its full future potential

Thin-Film AlN-on-Silicon Resonant Gyroscopes: Design, Fabrication, and Eigenmode Operation

Resonant MEMS gyroscopes have been rapidly adopted in various consumer, industrial, and automotive applications thanks to the significant improvements in their performance over the past decade. The current efforts in enhancing the performance of high-precision resonant gyroscopes are mainly focused on two seemingly contradictory metrics, larger bandwidth and lower noise level, to push the technology towards navigation applications. The key enabling factor for the realization of low-noise high-bandwidth resonant gyroscopes is the utilization of a strong electromechanical transducer at high frequencies. Thin-film piezoelectric-on-silicon technology provides a very efficient transduction mechanism suitable for implementation of bulk-mode resonant gyroscopes without the need for submicron capacitive gaps or large DC polarization voltages. More importantly, in-air operation of piezoelectric devices at moderate Q values allows for the cointegration of mode-matched gyroscopes and accelerometers on a common substrate for inertial measurement units. This work presents the design, fabrication, characterization, and method of mode matching of piezoelectric-on-silicon resonant gyroscopes. The degenerate in-plane flexural vibration mode shapes of the resonating structure are demonstrated to have a strong gyroscopic coupling as well as a large piezoelectric transduction coefficient. Eigenmode operation of resonant gyroscopes is introduced as the modal alignment technique for the piezoelectric devices independently of the transduction mechanism. Controlled displacement feedback is also employed as the frequency matching technique to accomplish complete mode matching of the piezoelectric gyroscopes.Ph.D

Reliability Testing Procedure for MEMS IMUs Applied to Vibrating Environments

The diffusion of micro electro-mechanical systems (MEMS) technology applied to navigation systems is rapidly increasing, but currently, there is a lack of knowledge about the reliability of this typology of devices, representing a serious limitation to their use in aerospace vehicles and other fields with medium and high requirements. In this paper, a reliability testing procedure for inertial sensors and inertial measurement units (IMU) based on MEMS for applications in vibrating environments is presented. The sensing performances were evaluated in terms of signal accuracy, systematic errors, and accidental errors; the actual working conditions were simulated by means of an accelerated dynamic excitation. A commercial MEMS-based IMU was analyzed to validate the proposed procedure. The main weaknesses of the system have been localized by providing important information about the relationship between the reliability levels of the system and individual components

National MEMS Technology Roadmap - Markets, Applications and Devices

MEMS teknologiaa on jo pitkään käytetty lukuisien eri laitteiden valmistamiseen. Osa näistä laitteista on ollut markkinoilla jo useita vuosia, kun taas osa on vasta kehitysvaiheessa. Jotta tutkimus ja kehitystyötä osattaisiin jatkossa kohdistaa oikeille painopistealueille, on tärkeää tietää mihin suuntaan kehitys on menossa. Tämä työ on osa kansallista MEMS teknologioiden tiekartta -projektia ja sen tavoitteena oli selvittää MEMS laitteiden kehityksen suuntaa. Työ toteutettiin laajana kirjallisuustutkimuksena. Lisäksi tulosten tueksi haastateltiin asiantuntijoita Suomen MEMS teollisuudesta. Työssä tarkasteltiin lukuisia jo markkinoilta löytyviä ja vasta kehitteillä olevia MEMS laitteita ja analysoitiin niitä sekä teknisestä että kaupallisesta näkökulmasta. Tutkimuksen perusteella kävi ilmi, että MEMS markkinat ovat pitkään muodostuneet vakiintuneista laitteista kuten mustesuihkupäistä, kiihtyvyysantureista, paineantureista sekä RF suotimista. Lisäksi mikrofonit, gyroskoopit ja optiset laitteet ovat olleet kaupallisesti saatavilla jo pitkään. Markkinat ovat hiljattain alkaneet tehdä tilaa myös uusille MEMS laitteille, joita tulee ulos nopeaa vauhtia. Viimeisimpänä markkinoille tulleita laitteita ovat erilaiset mikrofluidistiikka laitteet, mikrobolometrit sekä yhdistelmäanturit. Pian kaupallisesti saatavia laitteita ovat magnetometrit, automaattitarkennuslaitteet sekä MEMS oskillaattorit. Näiden laitteiden lisäksi kehitteillä on monia uusia MEMS laitteita, jotka saattavat tarjota merkittäviä mahdollisuuksia tulevaisuudessa. Kehitteillä olevia laitteita ovat erilaiset lääketieteelliset laitteet, atomikellot, mikrojäähdyttimet, mikrokaiuttimet, energiantuottolaitteet sekä RFID-laitteet. Kaikki kehitteillä olevista laitteista eivät välttämättä tule menestymään kaupallisesti, mutta jatkuva tutkimustyö osoittaa, että monilla MEMS laitteilla on potentiaalia useissa eri sovelluksissa. Markkinanäkökulmasta tarkasteltuna suurin potentiaali piilee kuluttajaelektroniikka markkinoilla. Muita tulevaisuuden kannalta potentiaalisia markkinoita ovat lääketieteelliset ja teollisuusmarkkinat. Tutkimus osoitti että MEMS laitteiden tutkimukseen ja kehitykseen liittyy monia potentiaalisia painopistealueita tulevaisuudessa. Käyttömahdollisuuksien parantamiseksi monet jo vakiintuneet laitteet kaipaavat vielä parannuksia. Toisaalta, jo olemassa olevia laitteita voidaan hyödyntää uusissa sovelluksissa. Lisäksi monet uusista ja kehitteillä olevista MEMS laitteista vaativat vielä kehitystyötä.MEMS technology has long been applied to the fabrication of various devices from which some have already been in use for several years, whereas others are still under development. In order to find future focus areas in research and development activities in the industry, it is important to know where the development is going. This thesis was conducted as a part of National MEMS technology roadmap, and it aimed for determining the evolution of MEMS devices. The work was conducted as an extensive literature review. In addition, experts from the Finnish MEMS industry were interviewed in order obtain a broader insight to the results. In this thesis various existing and emerging MEMS devices were reviewed and analyzed from technological and commercial perspectives. The study showed that the MEMS market has long been composed of established devices, such as inkjet print-heads, pressure sensors, accelerometers and RF filters. Also gyroscopes, microphones and optical MEMS devices have already been on the market for a long time. Lately, many new devices have started to find their place in the markets. The most recently introduced commercial devices include microfluidic devices, micro bolometers, and combo sensors. There are also a few devices including magnetometers, MEMS oscillators, and auto-focus devices that are currently crossing the gap from R&D to commercialization. In addition to the already available devices, many new MEMS devices are under development, and might offer significant opportunities in the future. These emerging devices include various bioMEMS devices, atomic clocks, micro-coolers, micro speakers, power MEMS devices, and RFID devices. All of the emerging devices might not find commercial success, but the constant stream shows, that there are numerous applications, where MEMS devices could be applied in. From a market point of view, the greatest potential in the future lies in consumer electronics market. Other highly potential markets include medical and industrial markets. The results of the thesis indicate that there are many potential focus areas in the future related to MEMS devices, including improvements of the existing devices in order to gain better utilization, application of the existing devices in new areas, and development work among the emerging devices

Monolithic sensor integration in CMOS technologies

© 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Besides being mainstream for mixed-signal electronics, CMOS technology can be used to integrate micro-electromechanical system (MEMS) on a single die, taking advantage of the structures and materials available in feature sizes around 180 nm. In this article, we demonstrate that the CMOS back-end-of-line (BEOL) layers can be postprocessed and be opportunistically used to create several kinds of MEMS sensors exhibiting good or even excellent performance, such as accelerometers, pressure sensors, and magnetometers. Despite the limitations of the available mechanical and material properties in CMOS technology, due to monolithic integration, these are compensated by the significant reduction of parasitics and system size. Furthermore, this work opens the path to create monolithic integrated multisensor (and even actuator) chips, including data fusion and intelligent processing.This work was supported in part by Baolab Microsystems; in part by the Spanish Ministry of Science, Innovation and Universities (MCIN); in part by the State Research Agency (AEI); in part by the European Social Fund (ESF) under Project RTI2018-099766-B-I00; in part by MCIN/AEI/10.13039/501100011033 under Grant PID2021-123535OB-I00; and in part by ERDF, “A way of making Europe.” The associate editor coordinating the review of this article and approving it for publication was Prof. Jean-Michel Redoute.Peer ReviewedPostprint (author's final draft

Fabrication of high aspect ratio vibrating cylinder microgyroscope structures by use of the LIGA process

Inertial grade microgyroscopes are of great importance to improve and augment inertial navigation systems based on GPS for industrial, automotive, and military applications. The efforts by various research groups worldwide to develop inertial grade microgyroscopes have not been successful to date. In 1994, the Department of Mechanical Engineering at Louisiana State University and SatCon Technology Corporation (Boston, Massachusetts) proposed a series of shock tolerant micromachined vibrating cylinder rate gyroscopes with aspect ratios of up to 250:1 to meet the needs of inertial navigation systems based on existing conventional vibrating cylinder gyroscopes. Each microgyroscope consisted of a tall thin shell metallic cylinder attached to a substrate at one end and surrounded by four drive- and four sense-electrodes. The proposed drive- and sense-mechanisms were capacitive-force and capacitance-change, respectively. Since the high aspect ratio metallic microgyroscope structures could not be fabricated by using traditional silicon-based MEMS processes, a LIGA-based two layer fabrication process was developed. A wiring layer was constructed by using a combination of thick film photolithography and electroplating (nickel and gold) on a silicon substrate covered with silicon nitride and a tri-layer plating base; aligned X-ray lithography and nickel electroplating were used to build the high aspect ratio cylinders and electrodes. Deficiencies in the LIGA process were also addressed in this research. Three types of X-ray mask fabrication processes for multi-level LIGA were developed on graphite, borosilicate glass and silicon nitride substrates. Stable and reliable gold electroplating methods for X-ray masks were also established. The plating rate and internal stress of deposits were thoroughly characterized for two brands of commercially available sulfite-based gold electroplating solutions, Techni Gold 25E and NEUTRONEX 309. The gaps between the cylinders and electrodes, which are defined by thin PMMA walls during electroplating, were found to be smaller than designed and deformed in many of the microgyroscope structures. The lateral dimensional loss (LDL) and deformation were identified to be related to the overall thickness and lateral aspect ratio (LAR) of the thin PMMA walls

Enhancements of MEMS design flow for Automotive and Optoelectronic applications

In the latest years we have been witnesses of a very rapidly and amazing grown of MicroElectroMechanical systems (MEMS) which nowadays represent the outstanding state-of-the art in a wide variety of applications from automotive to commercial, biomedical and optical (MicroOptoElectroMechanicalSystems). The increasing success of MEMS is found in their high miniaturization capability, thus allowing an easy integration with electronic circuits, their low manufacturing costs (that comes directly from low unit pricing and indirectly from cutting service and maintaining costs) and low power consumption. With the always growing interest around MEMS devices the necessity arises for MEMS designers to define a MEMS design flow. Indeed it is widely accepted that in any complex engineering design process, a well defined and documented design flow or procedure is vital. The top-level goal of a MEMS/MOEMS design flow is to enable complex engineering design in the shortest time and with the lowest number of fabrication iterations, preferably only one. These two characteristics are the measures of a good flow, because they translate directly to the industry-desirable reductions of the metrics “time to market” and “costs”. Like most engineering flows, the MEMS design flow begins with the product definition that generally involves a feasibility study and the elaboration of the device specifications. Once the MEMS specifications are set, a Finite Element Method (FEM) model is developed in order to study its physical behaviour and to extract the characteristic device parameters. These latter are used to develop a high level MEMS model which is necessary to the design of the sensor read out electronics. Once the MEMS geometry is completely defined and matches the device specifications, the device layout must be generated, and finally the MEMS sensor is fabricated. In order to have a MEMS sensor working according to specifications at first production run is essential that the MEMS design flow is as close as possible to the optimum design flow. The key factors in the MEMS design flow are the development of a sensor model as close as possible to the real device and the layout realization. This research work addresses these two aspects by developing optimized custom tools (a tool for layout check (LVS) and a tool for parasitic capacitances extraction) and new methodologies (a methodology for post layout simulations) which support the designer during the crucial steps of the design process as well as by presenting the models of two cases studies belonging to leading MEMS applications (a micromirror for laser projection system and a control loop for the shock immunity enhancement in gyroscopes for automotive applications)

MEMS Gyroscopes for Consumers and Industrial Applications

none2mixedAntonello, Riccardo; Oboe, RobertoAntonello, Riccardo; Oboe, Robert