A compact atomic magnetometer for cubesats

By shining a precisely tuned laser through an atomic vapor, we can determine local mag- netic field strength in scalar form and in a way that is not affected by temperature changes. This technology has been used in space many times before on missions flown by NASA and ESA, such as SWARM, Øersted, and CHAMP to calibrate accompanying vector mag- netometers which are subject to offsets caused by temperature changes. The device we constructed is a small, low-cost application of this scientific principle and opens up new areas of scientific possibility for cubesats and the ability to define geomagnetic field struc- tures on a small (<10km) scale as part of the ANDESITE cubesat mission being developed at Boston University. Previously, magnetic sensors in orbit have been flown individually on a single spacecraft or in very small groups such as the International Sun-Earth Exporers (ISEE) and SWARM which each used three separate spacecraft. This method of analyzing the geomagnetic field cannot provide a spatial or time resolution smaller than that of the separation between magnetic field readings. This project has focused on producing a tabletop demonstra- tion of a compact sensor head which could enable measurements on unprecedented small scales. Toward this end we have accomplished the construction and preliminary testing of a compact sensor head which contains all necessary elements to function as a scalar atomic magnetometer

CONCEPTION, TECHNOLOGIE ET PACKAGING DE CELLULES À VAPEUR DE CÉSIUM POUR LES HORLOGES ATOMIQUES DE TYPE MEMS

Atomic clocks are nowadays among the most accurate time and frequency standards, and are used, e.g.,for international time distribution service or in global navigation satellite systems. During the last severalyears, based on reliable and well-stabilized microelectromechanical systems (MEMS) technology and onthe availability of lasers on chip (single-mode vertical-cavity surface-emitting laser; VCSEL),considerable work has been performed by different groups around the world to develop miniaturizedversion of atomic clocks, called MEMS atomic clocks (MAC) or chip scale atomic clocks (CSAC).The goal of this thesis was to design and develop the technology of Cs vapor cells along with thermalanalysis for the thermal management of fully packaged Cs vapor cell for MEMS atomic clock. This workhas been carried-out in the framework of European project “MEMS atomic clock for timing, frequencycontrol and communication” (MAC-TFC). Two different architectures of Cs vapor cell have beenconsidered. The first one operates on the transmission of light through the cell and thus the Cs-vapor, andis called transmissive cell or T-cell. Such T-cell is made of silicon based deep-cavities sandwichedbetween two borosilicate glass wafers. For their fabrication, deep reactive ion etching (DRIE) process hasbeen optimized in order to produce smooth enough side walls of silicon cavities. In addition, specificanodic bonding process has been developed to fill the cavities with buffer gas at the required pressure.Second version of Cs vapor cell is based on the reflection of laser light inside the KOH etched siliconcavity sealed by one borosilicate glass wafer and is called reflective cell or R-cell. R-cells, as an advantageover the T-cells, allow e.g. a longer interaction of light/atom inside the Cs cavity, whereas location ofoptical source and detection elements on the same side of cell leads to better clock compactness. For theirfabrication, wet KOH etching, employed to realize the cavities inside the silicon with near mirror like(111) planes, has been studied and optimized. Further, diffraction gratings for routing of circularlypolarized light have been designed, fabricated and integrated on top of the Cs vapor R-cell. In bothversions of Cs vapor cells, our goal was to simplify the related clock assembly by doing maximumintegration and alignment at the wafer level, thanks to refractive and diffractive micro-optical componentswhile thermal analysis has been also performed for the thermal management of fully packaged Cs vaporcell (transmissive one) based on the Low temperature co-fired ceramics (LTTC) packaging.Les horloges atomiques sont de nos jours parmi les normes de temps et de fréquences les plus précises etsont utilisées, par exemple, pour les services de distributions travaillant à l'heure internationale ou pour lessystèmes de navigation globaux par satellite. Au cours des dernières années, un travail considérable a étéaccompli par différents groupes à travers le monde pour développer une version miniaturisée des horlogesatomiques, basée sur la technologie des systèmes microélectromécaniques qui est fiable, bien stabilisée etsur la disponibilité de lasers sur puces (diode laser monomode à cavité verticale émettant par la surface ouVCSEL : Vertical-Cavity surface emitting Laser). Ce type d'horloge atomique est appelé horloge atomiqueMEMS ou horloge atomique sur puce (CSAC : Chip Scale Atomic Clocks).L'objectif de cette thèse était de concevoir et développer la technologie des cellules à vapeur de Césium(Cs) ainsi qu’une analyse thermique pour sa gestion thermique lorsqu’elle est complètement packagéepour les horloges atomiques MEMS. Ce travail a été réalisé dans le cadre du projet européen "MEMSatomic clock for timing, frequency control and communication" (MAC-TFC). Deux conceptionsdifférentes de la cellule à vapeur de Cs ont été considérées. La première est basée sur la transmission de lalumière à travers la cellule et donc au travers de la vapeur de Cs et est appelée cellule transmissive ou T-cell. Ces T-cells sont réalisées à base de cavités profondes générées dans du silicium et prises en sandwichentre deux wafers de verre borosilicaté. Pour leur fabrication, le processus de gravure profonde par ionsréactifs (DRIE-Deep reactive ion etching) a été optimisé afin de produire des cavités dans le silicium dontles parois soient suffisamment lisses. De plus, le procédé de soudure anodique a été développé pourremplir les cavités avec du gaz tampon à la pression requise. La deuxième version de la cellule à vapeurde Cs est basée sur la réflection de la lumière du laser à l'intérieur des cavités gravées dans le silicium parKOH et scellées par un wafer de verre borosilicaté. Cette cellule est appelée cellule réfléchissante ou R-cell. Les R-cells permettent, par rapport aux T-cells, une interaction lumière/atome plus longue dans lescavités contenant du Cs, tandis que la localisation de la source optique et des éléments de détection dumême côté de la cellule permet la réalisation d’une horloge plus compacte. Pour leur fabrication, lagravure humide par KOH, employée pour générer les cavités à l'intérieur du silicium avec des parois dontla surface est proche de celle d’un miroir (111), a été étudiée et optimisée. De plus, les réseaux dediffraction pour le guidage de la lumière polarisée circulairement ont été conçus, fabriqués et intégrés surla partie supérieure de la R-cell à vapeur de Cs. Pour les deux versions des cellules à vapeur de Cs, notreobjectif était de simplifier l'assemblage relatif à l'horloge en faisant un maximum d'intégration et d'alignement à l'échelle du wafer, grâce à des composants micro-optiques réfractifs et diffractifs. Une analyse thermique a aussi été effectuée pour la gestion thermique de la cellule à vapeur de Cs complètement packagée (T-cell) à base de céramiques cofrittée à basse température (LTCC : Lowtemperature Co-fired ceramics)

Integrated packaging solutions and hotplates for a miniature atomic clock and other microsystems

This thesis aimed at developing innovative packaging solutions for a miniature atomic clock and other microsystems in the cm-scale, i.e. somewhat larger than what is practical for full "chip-scale" device-package integration using clean-room technologies for fabrication of microelectromechanical systems (MEMS). Besides well-defined and robust mechanical attachment, such packaging solutions must provide reliable electrical interconnection with the other system components, and, if needed, additional functions such as local temperature control, insulation from electrical magnetic or temperature perturbations, chemical separation (hermeticity). In order to accomplish this objective, different packaging technologies and modules were developed, fabricated and characterized in the frame of this thesis, with particular emphasis on the packaging of a miniature double-resonance (DR) rubidium atomic clock, which is an ideal demonstration platform given the associated large variety of requirements. First, the possibility of encapsulating the reactive Rb metal in ceramic / glass substrates using soldering was explored, with the aim to achieve simple and reliable fabrication of miniature atomic clock elements such as the reference cell and the Rb lamp. After a thorough literature review investigation of the metallurgical interactions between rubidium and materials used in packaging such as solder (Sn, Pb, Bi..) and thick-film metallizations metals (Ag, Pd, Au, 2 Pt...), an innovative design for a Rb reference cell (dimensions 10 × 12 mm ) is presented. The cell is based on a multifunctional low-temperature cofired ceramic (LTCC) spacer, closed by two glass windows allowing light transmission and acting as lids. Bonding is achieved by low-temperature soldering, avoiding exposing Rb to high temperatures. The use of LTCC as the main substrate material for Rb vapor cells in principle allows further integration of necessary functions for the Rb lamp and reference cell, such as temperature regulation, excitation / microwave resonator electrodes, impedance-matching passive components (lamp), and coil for static magnetic field generation (reference). In this work, to test the hermeticity of the bonding, a pressure sensor was integrated into the cell by replacing one of the glass windows by a membrane comprising an integrated piezoresistive Wheatstone bridge. In this frame, a new lamination technique for LTCC is proposed. The technique consists in applying a hot-melt adhesive on top of the LTCC green tape, and allows good bonding of the tapes even at low lamination pressure. This technique is particularly attractive for the lamination of LTCC microfluidic devices or membrane pressure sensors, because the low pressure applied during lamination does not affect the shape of the channels in a microfluidic device, or the membrane of the sensor. The resulting cells are shown to be hermetic, and a Rb response could be measured by the project partners. However, heating resulted in loss of this response, indicating Rb depletion by undesired reactions between Rb and the sealing metals or contaminants. This result is somewhat in line with studies made in parallel with the present work on low-temperature indium thermocompression bonding. Therefore, although the results are promising, further optimisation of metallizations, solders and package design is required. An important generic function that may be integrated into LTCC is temperature control. In this frame, a multifunctional LTCC hotplate was designed, fabricated and studied. This device allows controlling the temperature of any object in the cm-scale, such as the abovementioned Rb vapor cells (reference or lamp) and other temperature-sensitive elements used in miniature atomic clocks such as lasers and impedance-matching passive components. Full thermal analysis, mathematical calculations, finite-element simulations and laboratory experiments were performed. The excellent structurability and modest thermal conductivity of LTCC make it much better suited than standard alumina for integrated hotplates, resulting in conduction losses in the LTCC structure being small compared to surface losses by conduction and convection. It is therefore concluded that insulation and/or vacuum packaging techniques are necessary to achieve optimized low-power operation. Although we have seen that LTCC is an excellent integrated packaging platform, there are some limitations for carrying relatively massive components such as the DR atomic clock resonator cavity structure, which in general is a solid metal part. Therefore, an alternative hotplate technology platform, was developed, based on the combination of standard fiberglass-reinforced organic-matrix printed-circuit board (PCB), combined with thick-film alumina heaters. The PCB acts as high-strength, low-cost and readily available mechanical carrier, electrical interconnect and thermal insulator, and the thick-film heaters provide local temperature regulation, with the high thermal conductivity of alumina ensuring good local temperature uniformity. Therefore, such a hybrid PCB-Al2O3 platform constitutes an attractive alternative to LTCC hotplates for benign operating conditions. In conclusion, this work introduced several innovative packaging solutions and techniques, which were successfully applied to various dedicated modules carrying the elements of miniature atomic clocks. Beyond this application, these developments allow us to envision efficient packaging of a wide variety of new miniature devices. Also, new areas for further investigations are suggested, such as long-term metallurgical interactions of alkali metals with solders, hermeticity, optimization of temperature distribution and thermal insulation techniques, as well as reliability at high-temperatures and under severe thermal cycling.This thesis aimed at developing innovative packaging solutions for a miniature atomic clock and other microsystems in the cm-scale, i.e. somewhat larger than what is practical for full "chip-scale" device-package integration using clean-room technologies for fabrication of microelectromechanical systems (MEMS). Besides well-defined and robust mechanical attachment, such packaging solutions must provide reliable electrical interconnection with the other system components, and, if needed, additional functions such as local temperature control, insulation from electrical magnetic or temperature perturbations, chemical separation (hermeticity). In order to accomplish this objective, different packaging technologies and modules were developed, fabricated and characterized in the frame of this thesis, with particular emphasis on the packaging of a miniature double-resonance (DR) rubidium atomic clock, which is an ideal demonstration platform given the associated large variety of requirements. First, the possibility of encapsulating the reactive Rb metal in ceramic / glass substrates using soldering was explored, with the aim to achieve simple and reliable fabrication of miniature atomic clock elements such as the reference cell and the Rb lamp. After a thorough literature review investigation of the metallurgical interactions between rubidium and materials used in packaging such as solder (Sn, Pb, Bi..) and thick-film metallizations metals (Ag, Pd, Au, 2 Pt...), an innovative design for a Rb reference cell (dimensions 10 × 12 mm ) is presented. The cell is based on a multifunctional low-temperature cofired ceramic (LTCC) spacer, closed by two glass windows allowing light transmission and acting as lids. Bonding is achieved by low-temperature soldering, avoiding exposing Rb to high temperatures. The use of LTCC as the main substrate material for Rb vapor cells in principle allows further integration of necessary functions for the Rb lamp and reference cell, such as temperature regulation, excitation / microwave resonator electrodes, impedance-matching passive components (lamp), and coil for static magnetic field generation (reference). In this work, to test the hermeticity of the bonding, a pressure sensor was integrated into the cell by replacing one of the glass windows by a membrane comprising an integrated piezoresistive Wheatstone bridge. In this frame, a new lamination technique for LTCC is proposed. The technique consists in applying a hot-melt adhesive on top of the LTCC green tape, and allows good bonding of the tapes even at low lamination pressure. This technique is particularly attractive for the lamination of LTCC microfluidic devices or membrane pressure sensors, because the low pressure applied during lamination does not affect the shape of the channels in a microfluidic device, or the membrane of the sensor. The resulting cells are shown to be hermetic, and a Rb response could be measured by the project partners. However, heating resulted in loss of this response, indicating Rb depletion by undesired reactions between Rb and the sealing metals or contaminants. This result is somewhat in line with studies made in parallel with the present work on low-temperature indium thermocompression bonding. Therefore, although the results are promising, further optimisation of metallizations, solders and package design is required. An important generic function that may be integrated into LTCC is temperature control. In this frame, a multifunctional LTCC hotplate was designed, fabricated and studied. This device allows controlling the temperature of any object in the cm-scale, such as the abovementioned Rb vapor cells (reference or lamp) and other temperature-sensitive elements used in miniature atomic clocks such as lasers and impedance-matching passive components. Full thermal analysis, mathematical calculations, finite-element simulations and laboratory experiments were performed. The excellent structurability and modest thermal conductivity of LTCC make it much better suited than standard alumina for integrated hotplates, resulting in conduction losses in the LTCC structure being small compared to surface losses by conduction and convection. It is therefore concluded that insulation and/or vacuum packaging techniques are necessary to achieve optimized low-power operation. Although we have seen that LTCC is an excellent integrated packaging platform, there are some limitations for carrying relatively massive components such as the DR atomic clock resonator cavity structure, which in general is a solid metal part. Therefore, an alternative hotplate technology platform, was developed, based on the combination of standard fiberglass-reinforced organic-matrix printed-circuit board (PCB), combined with thick-film alumina heaters. The PCB acts as high-strength, low-cost and readily available mechanical carrier, electrical interconnect and thermal insulator, and the thick-film heaters provide local temperature regulation, with the high thermal conductivity of alumina ensuring good local temperature uniformity. Therefore, such a hybrid PCB-Al2O3 platform constitutes an attractive alternative to LTCC hotplates for benign operating conditions. In conclusion, this work introduced several innovative packaging solutions and techniques, which were successfully applied to various dedicated modules carrying the elements of miniature atomic clocks. Beyond this application, these developments allow us to envision efficient packaging of a wide variety of new miniature devices. Also, new areas for further investigations are suggested, such as long-term metallurgical interactions of alkali metals with solders, hermeticity, optimization of temperature distribution and thermal insulation techniques, as well as reliability at high-temperatures and under severe thermal cycling

NASA Tech Briefs, April 2005

Gas-Tolerant Device Senses Electrical Conductivity of Liquid Nanoactuators Based on Electrostatic Forces on Dielectrics Replaceable Microfluidic Cartridges for a PCR Biosensor CdZnTe Image Detectors for Hard-X-Ray Telescopes High-Aperture-Efficiency Horn Antenna Full-Circle Resolver-to-Linear-Analog Converter Continuous, Full-Circle Arctangent Circuit Advanced Three-Dimensional Display System Automatic Focus Adjustment of a Microscope Topics covered include: FastScript3D - A Companion to Java 3D; Generating Mosaics of Astronomical Images; Simulating Descent and Landing of a Spacecraft; Simulating Vibrations in a Complex Loaded Structure; Rover Sequencing and Visualization Program; Software Template for Instruction in Mathematics; Support for User Interfaces for Distributed Systems; Nanostructured MnO2-Based Cathodes for Li-Ion/Polymer Cells; Multi-Layer Laminated Thin Films for Inflatable Structures; Two-Step Laser Ranging for Precise Tracking of a Spacecraft; Growing Aligned Carbon Nanotubes for Interconnections in ICs; Multilayer Composite Pressure Vessels; Texturing Blood-Glucose-Monitoring Optics Using Oxygen Beams; Fault-Tolerant Heat Exchanger; Atomic Clock Based on Opto-Electronic Oscillator; Microfocus/Polycapillary-Optic Crystallographic X-Ray Sys; Depth-Penetrating Luminescence Thermography of Thermal- Barrier Coatings; One-Dimensional Photonic Crystal Superprisms; Measuring Low-Order Aberrations in a Segmented Telescope; Mapping From an Instrumented Glove to a Robot Hand; Application of the Hilbert-Huang Transform to Financial Data; Optimizing Parameters for Deep-Space Optical Communication; and Low-Shear Microencapsulation and Electrostatic Coating

Photodetectors

In this book some recent advances in development of photodetectors and photodetection systems for specific applications are included. In the first section of the book nine different types of photodetectors and their characteristics are presented. Next, some theoretical aspects and simulations are discussed. The last eight chapters are devoted to the development of photodetection systems for imaging, particle size analysis, transfers of time, measurement of vibrations, magnetic field, polarization of light, and particle energy. The book is addressed to students, engineers, and researchers working in the field of photonics and advanced technologies

INSPIRESat-1: An Ionosphere and Solar X-ray Observing MicroSat

The International Satellite Program in Research and Education’s (INSPIRE) first satellite is an Ionosphere and Solar X-ray observing microsat slated for launch in November of 2019 onboard an ISRO Polar Satellite Launch Vehicle. The microsat has a mission specific structure fitting on a PSLV ring deployer. There are two payloads aboard with two different science objectives. The Compact Ionosphere Probe (CIP) will take in-situ measurements of ion density, composition, temperature, velocity, and electron temperature. The CIP is a smaller version of the Advanced Ionosphere Probe (AIP, both developed in Taiwan) currently operating onboard the FORMOSat-5. This instrument is capable of sampling the ionosphere at 1 and 8 Hz. The second payload is the Dual Aperture X-ray Solar spectrometer (DAXSS). DAXSS is a modified Amptek X123 that will observe Solar X-rays, specifically soft X-rays. Hot plasma in the sun’s corona is best measured in the soft X-rays. Many emission lines for important elements (Fe, Si, Mg, S, etc) are in the soft X-ray range. Soft X-rays are always present in the sun but 100 times brighter during flares, these observations will also lend to understanding the temperature difference between the sun’s corona and photosphere. The solar soft x-rays are also important for the Earth’s Ionosphere, adding to the ionosphere observations made by CIP. The DAXSS instrument has heritage from a NASA calibration rocket experiment and two cubesats, MINXSS 1 and 2. The newer model Amptek X123 has much improved energy resolution for the X-ray spectrum. The primary science objectives of the INSPIRESat-1 are twofold. First, enabling the characterization of the temporal and spatial distributions of small-scale plasma irregularities like plasma bubbles and the Midnight Temperature Maximum (MTM) in season, location, and time by CIP. Second, giving a greater understanding of why the Sun’s corona is orders of magnitude hotter than the photosphere, why there is an abundance of elements change during different solar events, and how these events (observed with greater soft x-ray fidelity) effect the earth’s ionosphere. In this paper, we present science expectations for the INSPIRESat-1 and a concept for coordinated Ionospheric measurements covering several altitudes and local times using three satellite platforms carrying the same CIP instrument (INSPIRESat-1, IDEASat/INSPIRESat-2, INSPIRESat-4, FORMOSat-5). We describe the development of DAXSS and how the dual aperture prevents the need for two X123 to get the similar data. We also highlight the unique development of the INSPIRESat-1 microsat being developed by international collaboration across three different universities

Technology development for a compact rubidium optical frequency reference

The precision and accuracy of navigation and radar systems is typically limited by the stability of their internal frequency references. Currently, microwave atomic frequency references are close to the limits of what they can achieve in terms of short term stability. Optical atomic frequency references have demonstrated several orders of magnitude improvement in both short-term as well as long-term stability. In the past decade, improvements in optical frequency comb (OFC) technology have enabled the precise measurement of optical frequencies with much smaller form-factors, spurring research to build a portable optical atomic clock referenced to the 87Rb 5S1=2; F = 2 ! 5D5=2; F0 = 4 two-photon transition (TPT). Using a single laser source and simple Doppler-free spectroscopy in a heated Rb vapour cell one can generate an atomic reference signal with a linewidth approaching 334 kHz. The research presented here, compares the suitability of a telecoms (1550-1560 nm) CW laser with a narrow bandwidth OFC laser of 10-20 modes spaced apart at 3-6 GHz frep. The OFC laser achieves more than double the second harmonic conversion effciency compared with the CW laser, while delivering up to 30 mW of 778 nm light. The 778 nm OFC is then used to excite the reference transition and demonstrate coherent interaction of all OFC modes. Towards the aim of making the system compact, the research explores the use of micro-fabricated vapour cells, 3D printed oven designs and a chip-scale DFB (distributed feedback) laser with the prospects of integrating both the laser and spectroscopy on to a single micro-fabricated semiconductor platform. Pre-stabilising a noisy laser to an optical cavity is commonly required for optical atomic clocks, in order to resolve narrow-linewidth transitions. Towards this application, a low-drift, all-metal optical cavity is developed and characterised using Allvar metal, which possesses a negative coe�cient of thermal expansion (CTE). The overall cavity CTE can be temperature tuned to yield a CTE of < 0.001 ppm/°C at � 27 °C. The long-term cavity mode stability of the cavity was measured while referenced to one of the 87Rb 5S1=2 ! 5P3=2 780 nm transitions, residual drifts of 0.3 MHz/hr on time-scales up to 5 hrs (after subtracting o� pressure-correlated frequency shifts). The all-metal cavity should be less sensitive to thermal gradients as well as more responsive temperature stabilisation than ultra-low expansion cavities.The precision and accuracy of navigation and radar systems is typically limited by the stability of their internal frequency references. Currently, microwave atomic frequency references are close to the limits of what they can achieve in terms of short term stability. Optical atomic frequency references have demonstrated several orders of magnitude improvement in both short-term as well as long-term stability. In the past decade, improvements in optical frequency comb (OFC) technology have enabled the precise measurement of optical frequencies with much smaller form-factors, spurring research to build a portable optical atomic clock referenced to the 87Rb 5S1=2; F = 2 ! 5D5=2; F0 = 4 two-photon transition (TPT). Using a single laser source and simple Doppler-free spectroscopy in a heated Rb vapour cell one can generate an atomic reference signal with a linewidth approaching 334 kHz. The research presented here, compares the suitability of a telecoms (1550-1560 nm) CW laser with a narrow bandwidth OFC laser of 10-20 modes spaced apart at 3-6 GHz frep. The OFC laser achieves more than double the second harmonic conversion effciency compared with the CW laser, while delivering up to 30 mW of 778 nm light. The 778 nm OFC is then used to excite the reference transition and demonstrate coherent interaction of all OFC modes. Towards the aim of making the system compact, the research explores the use of micro-fabricated vapour cells, 3D printed oven designs and a chip-scale DFB (distributed feedback) laser with the prospects of integrating both the laser and spectroscopy on to a single micro-fabricated semiconductor platform. Pre-stabilising a noisy laser to an optical cavity is commonly required for optical atomic clocks, in order to resolve narrow-linewidth transitions. Towards this application, a low-drift, all-metal optical cavity is developed and characterised using Allvar metal, which possesses a negative coe�cient of thermal expansion (CTE). The overall cavity CTE can be temperature tuned to yield a CTE of < 0.001 ppm/°C at � 27 °C. The long-term cavity mode stability of the cavity was measured while referenced to one of the 87Rb 5S1=2 ! 5P3=2 780 nm transitions, residual drifts of 0.3 MHz/hr on time-scales up to 5 hrs (after subtracting o� pressure-correlated frequency shifts). The all-metal cavity should be less sensitive to thermal gradients as well as more responsive temperature stabilisation than ultra-low expansion cavities

Glassy Materials Based Microdevices

Microtechnology has changed our world since the last century, when silicon microelectronics revolutionized sensor, control and communication areas, with applications extending from domotics to automotive, and from security to biomedicine. The present century, however, is also seeing an accelerating pace of innovation in glassy materials; as an example, glass-ceramics, which successfully combine the properties of an amorphous matrix with those of micro- or nano-crystals, offer a very high flexibility of design to chemists, physicists and engineers, who can conceive and implement advanced microdevices. In a very similar way, the synthesis of glassy polymers in a very wide range of chemical structures offers unprecedented potential of applications. The contemporary availability of microfabrication technologies, such as direct laser writing or 3D printing, which add to the most common processes (deposition, lithography and etching), facilitates the development of novel or advanced microdevices based on glassy materials. Biochemical and biomedical sensors, especially with the lab-on-a-chip target, are one of the most evident proofs of the success of this material platform. Other applications have also emerged in environment, food, and chemical industries. The present Special Issue of Micromachines aims at reviewing the current state-of-the-art and presenting perspectives of further development. Contributions related to the technologies, glassy materials, design and fabrication processes, characterization, and, eventually, applications are welcome