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Metal Nanoparticles Deposition On Biological And Physical Scaffolds To Develop A New Class Of Electronic DevicesBerry, Vikas 10 October 2006 (has links)
Nanoparticle based devices are becoming of great interest because of their single-electron transport behavior, and high surface charge density. Nanoparticle based devices operate at low power, and are potentially highly stable and extremely robust. Making interconnections to nanoparticle devices, however, has been an impending issue. Also percolating/conductive array of nanoparticles is not easy to build since repulsion between the charged nanoparticles causes them to deposit at distance significantly larger for electron tunneling. In this study, we resolve these challenges to make nanoparticle based electronic devices. Using biological (bacteria) or physical (polyelectrolyte fiber) scaffolds, we selectively deposited percolating array of 30 nm Au nanoparticles, to produce a highly versatile nanoparticle-organic hybrid device. The device is based on electron tunneling phenomena, which is highly sensitive to change in inter-particle distance and dielectric constant between nanoparticles. The key to building this structure is the molecular brushes on the surface of the scaffold, which shield the charge on nanoparticle to allow for percolating deposition. The electrostatic attraction for such a deposition on bacteria was measured to be so strong (0.038 N/m) that it could bend a 400 nm long and 25 nm wide gold nanorod. Once the device is built, the hygroscopic scaffolds were actuated by humidity, to modulate the electron tunneling barrier width (or height) between the metallic nanoparticles. A decrease in inter-particle separation by < 0.2 nm or a change in the dielectric constant from ~ 40 to 3 (for humidity excursion from 20% to ~0%), causes a 40-150 fold increase in electron tunneling current. The coupling between the underlying scaffold and the Au particle structure is essential to achieving such a high and robust change in current. In contrast to most humidity sensors, the sensitivity is extremely high at low humidity. This device is >10-fold better than standard microelectronic and MEMS technology based humidity sensors. After the deposition, the "live" bacterial scaffold retains its biological construct, providing an avenue for active integration of biological functions with electronic transport in nanoparticle device. Such hybrids will be the key to conceptually new electronic devices that can be integrated with power and function of microorganisms, on flexible plastic-like substrates using simple beaker chemistry. The technology has broad potential based on variety of nanoparticles (for example, magnetic, metallic and semi-conducting) to make electro-optical and inorganic devices, bringing a prominent advancement in the present technology. Our work is published in, Angewandte Chemie, JACS and Nano Letters, and featured in places such as, Discover Magazine, Science News and Nature. / Ph. D.
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Analysis by Meshless Local Petrov-Galerkin Method of Material Discontinuities, Pull-in Instability in MEMS, Vibrations of Cracked Beams, and Finite Deformations of Rubberlike MaterialsPorfiri, Maurizio 08 May 2006 (has links)
The Meshless Local Petrov-Galerkin (MLPG) method has been employed to analyze the following linear and nonlinear solid mechanics problems: free and forced vibrations of a segmented bar and a cracked beam, pull-in instability of an electrostatically actuated microbeam, and plane strain deformations of incompressible hyperelastic materials. The Moving Least Squares (MLS) approximation is used to generate basis functions for the trial solution, and for the test functions. Local symmetric weak formulations are derived, and the displacement boundary conditions are enforced by the method of Lagrange multipliers. Three different techniques are employed to enforce continuity conditions at the material interfaces: Lagrange multipliers, jump functions, and MLS basis functions with discontinuous derivatives. For the electromechanical problem, the pull-in voltage and the corresponding deflection are extracted by combining the MLPG method with the displacement iteration pull-in extraction algorithm. The analysis of large deformations of incompressible hyperelastic materials is performed by using a mixed pressure-displacement formulation. For every problem studied, computed results are found to compare well with those obtained either analytically or by the Finite Element Method (FEM). For the same accuracy, the MLPG method requires fewer nodes but more CPU time than the FEM. / Ph. D.
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Instabilities in Multiphysics Problems: Micro- and Nano-electromechanical Systems, and Heat-Conducting Thermoelastoviscoplastic SolidsSpinello, Davide 03 October 2006 (has links)
We investigate (i) pull-in instabilities in a microelectromechanical (MEM) beam due to the Coulomb force and in MEM membranes due to the Coulomb and the Casimir forces, and (ii) thermomechanical instability in a heat-conducting thermoelastoviscoplastic solid due to thermal softening overcoming hardening caused by strain- and strain-rate effects. Each of these nonlinear multiphysics problems is analyzed by the meshless local Petrov-Galerkin (MLPG) method. The moving least squares (MLS) approximation is used to generate basis functions for the trial solution, and the basis for test functions is taken to be either the weight functions used in the MLS approximation, or the same as for the trial solution. In this case the method becomes Bubnov-Galerkin. Essential (displacement, temperature, electric potential) boundary conditions are enforced by the method of Lagrange multipliers. For the electromechanical problem, the pull-in voltage and the corresponding deflection are extracted by combining the MLPG method with either the displacement iteration pull-in extraction algorithm or the pseudoarclength continuation method. For the thermomechanical problem, the localization of deformation into narrow regions of intense plastic deformation is delineated. For every problem studied, computed results are found to compare well with those obtained either analytically or by the finite element (FE) method. For the same accuracy, the MLPG method generally requires fewer nodes but more CPU time than the FE method; thus additional computational cost is compensated somewhat by the increased efficiency of the MLPG method. / Ph. D.
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Vehicle Axle Detection and Spacing Calibration Using MEMS AccelerometerZhang, Wei 05 December 2014 (has links)
Vehicle classification data especially trucks has an important role in both pavement maintenance and highway planning strategy. An advanced microelectromechanical system (MEMS) accelerometer for vehicle classification based on axle count and spacing was designed, tested, and applied to the pavement. Vehicle-pavement interaction was collected by the vibration sensor while vehicle axle count and spacing were calibrated later. Collected vibration data also used to analyze the pavement surface condition and compared with simulation using dynamic loading analysis. Laboratory tests using MMLS3 device to verify the accuracy of MEMS accelerometer and reaction under different surface condition were tested. An algorithm for calculating axle spacing and axle count was developed. Acceleration of different pavement surface condition were analyzed and compared with simulation results, the influence of surface condition to the pavement acceleration was concluded. / Master of Science
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Modeling the Thermal Performance of an Intelligent MEMS Pressure Sensor with Self-Calibration CapabilitiesDe Clerck, Albrey Paul 23 October 2020 (has links)
Recent industry trends toward more complex and interconnected systems have increased the demand for more reliable pressure sensors. One of the best methods to ensure reliability is by regularly calibrating the sensor, checking its functionality and accuracy. By integrating a micro-actuator with a pressure sensor, the sensor can self-calibrate, eliminating the complexities and costs associated with traditional sensor calibration methods. The present work is focused on furthering understanding and improving the thermal performance of a thermopneumatic actuated self-calibrating pressure sensor.
A transient numerical model was developed in ANSYS and was calibrated using experimental testing data. The model provided insights into the sensor's performance not previously observed in experimental testing, such as the temperature gradient within the sensor and its implications. Furthermore, the model was utilized for two design studies. First, the sensor's inefficiencies were studied, and it was found that a substrate with low thermal conductivity and high thermal diffusivity is ideal for both the sensor's efficiency and a faster transient response time. The second design study showed that decreasing the size of the sealed reference cavity, decreases power consumption and transient response time. The study also showed that decreasing the cavity base dimension has a larger effect on decreasing power consumption and response time. Overall, the present work increases understanding of the self-calibrating pressure sensor and provides insight into potential design improvements, moving closer to true self-calibrating pressure sensors. / Master of Science / Pressure sensors are used in most engineering applications, and the demand is ever increasing due to emerging fields such as the Internet of things (IOT), automations, and autonomy. One drawback of current pressures sensor technology is their need to be calibrated, ensuring accuracy and function. Sensor calibration requires equipment, trained personnel, and must be done regularly, resulting in significant costs. Borrowing technology, methods, and materials from the integrated circuit industry, the costs of sensor calibration can be addressed by the development of an intelligent MEMS (micro-electromechanical system) pressure sensor with self-calibration capabilities. The self-calibrating capability is achieved by combining a micro-actuator and a micro- pressures sensor into one system.
This work focuses on complementing previously obtained experimental testing data with a thermal finite element model to provide a deeper understanding and insight. The model is implemented in the commercial software ANSYS and model uncertainties were addressed via model calibration. The model revealed a temperature gradient within the sensor, and insight into its potential effects.
The model is also used as a design tool to reduce energy inefficiencies, decrease the time it takes the sensor to respond, and to study the effects of reducing the sensor size. The studies showed that the power consumption can potentially be decreased up to 92% and the response time can be decreased up to 99% by changing the sensor's substrate material. Furthermore, by halving the sensor reference cavity size, the cavity temperature can be increased by 45% and the time for the sensor to respond can be decrease by 59%.
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Chameleon Interference: Assessing Vulnerability of Magnetic Sensors to Spoofing and Signal injection attacks through Environmental interference in Mobile DevicesGleason, David Theodore 06 January 2023 (has links)
Embedded sensors are a fixture of most devices in the current computer industry. These small devices are used for a variety of purposes throughout many fields to collect whatever kind of information is needed by the user. From data on device acceleration to data on position relative to the Earth's magnetic field, embedded sensors can provide it for any number of tasks.
The advent of these devices has made work and research in the computer industry significantly easier but they are not without their drawbacks.
Most of these sensors operate by drawing external data from the environment through send and receive signals. This mode of operation leaves them vulnerable to external malicious users who seek access to the data being stored and handled by the sensors. Concerns over security and privacy of embedded sensor data has become a topic of great concern with the continued digitization of sensitive personal data.
Within the last five years, studies have shown the ability to manipulate embedded magnetic sensors in order to gain access to various forms of sensitive personal data. This is of great concern to the developers of mobile devices as most mobile devices possess embedded magnetic sensors. The vulnerability of sensors to external influence leads to concerns for both data privacy and degradation of public trust in the ability of their devices to keep their personal information safe and out of the wrong hands. Degradation of public trust in security methodologies is a major concern to many in the research and tech industry as much of the work conducted to advance both security and technology depends on large amounts of public data. If the public loses trust in the ability of the devices used by researchers to protect and ensure the safety of the data provided to them, then they may stop providing data which would then make the work of researchers and other tech workers considerably more difficult.
To address these concerns, this thesis will present an introduction to Magnetic sensor devices (a prominent tool for data collection), how these sensors work and the ways they handle data. We shall then examine the techniques used to interfere with the functioning and output of magnetic sensors employed by mobile devices. Finally, we shall examine existing techniques for defending against these kinds of attacks as well as propose potential new techniques. The end goal of this work is to provide a broader perspective on the nature of environmental/natural interference and its relationship to scientific study and technological advancement. Literature around this topic does exist, however, all existing works currently in the literature focus exclusively on one form of interference i.e., light which leads to a smaller/narrower perspective which this work seeks to remedy. The end result is meant to give a broader perspective of multiple forms of interference and their interrelations between each other than is possible by current perspectives due to their narrow lens. / Master of Science / Embedded sensors are small devices integrated into many mobile devices currently in the public market. These devices serve to collect environmental data of all kinds in order to perform a variety of functions. From directional calibration to magnetic orientation in relation to the magnetic north pole, sensors perform it all. This has led to a massive increase in computer power and quality of life for the general public but not without issue. The increase in storing personal/sensitive data to be processed by these devices has prompted a new breed of privacy concerns and problems to confront. In this thesis, we seek to show the influence and effects of five distinct types of interference rooted in the natural world on the functioning of magnetic sensor devices.
Through the experiments conducted in this work, it was found that the interference forms of sound, temperature, and electromagnetism could induce a 32-36 percent average decrease in standard deviation in the data being processed by the sensor. Temperature shifting as an interference form also showed the potential for sizeable impacts on sensor functioning in terms of both increases and decreases. The largest decrease in standard deviation observed was 122 percent from the experiments with low temperature shifting. This work shows the incredible power and influence that the forces of nature can have on everyday devices and their need for data from their environment. The results observed from the temperature shift experiments also highlight the danger of leaving temperature based cyber-attacks under researched. The main use of this work is to fill the void in the current literature created by temperature based cyber-attacks and hopefully spur more research to be conducted into this method of cyber threat.
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Reduction of Unsteady Stator-Rotor Interaction by Trailing Edge Blowing Using MEMS Based MicrovalvesRao, Nikhil M. 30 April 1999 (has links)
This research performs an experimental study of a trailing edge blowing system that can adapt to variations in flow parameters and reduce the unsteady stator-rotor interaction at all engine operating conditions. The fan rotor of a 1/14 scale turbofan propulsion simulator is subjected to spatially periodic, circumferential inlet flow distortions. The distortions are generated by four struts that support a centerbody in the inlet mounted onto the simulator. To reduce the unsteady effects of the strut wakes on the rotor blades, the wake is re-energized by injecting mass from the trailing edge of the strut. Each strut is provided with discrete blowing holes that open out through the strut trailing edge. Each blowing hole is connected to a MEMS based microvalve, which controls the blowing rate of the hole. The microvalve is actuated by a signal voltage, generated by a PID controller that accepts free stream and wake axial flow velocities as inputs and minimizes their difference. To quantify the effectiveness of trailing edge blowing the far-field noise is measured in an anechoic chamber. The experiments are performed for two simulator test speeds, 29,500 rpm and 40,000 rpm, with and without trailing edge blowing. The maximum reduction recorded at 29,500 rpm is 8.2 dB, and at 40,000 rpm is 7.3 dB. Reductions of 2.9 dB and greater are observed at the first five harmonics of the blade passing frequency. The sound power level at the blade passing frequency, calculated from measured far-field directivity, is reduced by 4.4 dB at 29,500 rpm and by 2.9 dB at 40,000 rpm. The feasibility and advantage of active control is demonstrated by the ability of the system to respond to a step change in the inlet flow velocity, and achieve optimum wake filling in approximately 8 seconds. / Master of Science
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Design and Fabrication of Polymer/Graphene Laminate Thin FilmsCroft, Zacary Lane 05 September 2024 (has links)
The development of graphene-based electronics may produce a new generation of electronic devices with enhanced performance over traditional materials. However, quality graphene electronics will require large-area, continuous graphene film produced by chemical vapor deposition (CVD), which is typically not stable when free-standing. Instead, CVD graphene may be coupled with polymer thin films to produce polymer/graphene laminates (PGLs), which show improved mechanical stability and good electrical conductivity over large areas. For example, single-layer graphene (SLG) has been coupled with polyetherimide (PEI) to produce thin film audio speakers with significantly enhanced energy efficiency compared to traditional speaker designs. However, the poor design and fabrication of PGLs may degrade the interfacial interactions of polymers with graphene and make the interface more susceptible to deformation. Interfacial weakening then limits their long-term reliability and performance in micro- and nano-electromechanical systems (MEMS/NEMS), in which materials are constantly subjected to dynamic loads. In this dissertation, we construct a framework for developing PGL thin films with controlled interfacial properties based on the rational design of polymer substrates and careful consideration of fabrication-induced defects. We evaluate this framework from several angles. First, the design of PEI/SLG film thickness is explored for controlling mechanical mixing and composite Young's modulus. Then, the role of thermal annealing during PEI/SLG fabrication is examined and its effect of mechanical mixing studied. Finally, we investigate mechanical fatigue in PEI/SLG thin films under dynamic loading with different pre-tensions.
The design of mechanical properties in PGLs is crucial for ensuring long-term stability and operational performance. The Young's modulus is an important mechanical parameter governed by mechanical mixing in PGLs, and better mechanical mixing is facilitated by improved stress transfer efficiency at the polymer/graphene interface. Thus, the control of mechanical mixing through PGL design is an important research topic for developing PGL thin films with good mechanical performance. To this end, we evaluated the design of PEI/SLG thin films with precisely controlled thicknesses to afford control over mechanical mixing and the composite Young's modulus. PEI concentrations of 3–6 wt% were used to spin-coat PEI/SLG films at precisely controlled thicknesses of ~200–1000 nm, which enabled the design of PEI/SLG thin films based on thickness control. The design of PEI/SLG film thickness afforded control over the volume fraction of SLG, which is related to the composite Young's modulus of the films via the well-known mixing rule. To validate this approach, we measured the composite Young's modulus of PEI/SLG films and modelled the relationship between modulus and film thickness (i.e., volume fraction) using the mixing rule. However, we found that linear regression analysis yielded an unexpectedly high effective Young's modulus of 1.12 ± 0.05 TPa for SLG. Further investigation revealed the larger-than-expected value was due to the gradual deterioration of mechanical mixing between SLG and PEI at film thicknesses > 250 nm. Overall, our results demonstrate that the control of mechanical mixing in PGL thin films is achievable through the physical design of film thickness, which fits well within the proposed framework for PGL development.
The fabrication of PGL materials is another important topic for controlling PGL properties. For example, the transfer process required for removing PGL thin films from a CVD substrate is known to introduce mechanical defects and electronic doping if improper processing conditions are used. However, little is known about the impact of thermal annealing on the properties of PGL materials. Normally, thermal annealing is thought to aid in the removal solvent and stress after polymer deposition on SLG, but we show that thermal annealing instead induces substantial structural damage and reduced film properties when poor conditions are used. Specifically, thermally annealing PEI/SLG in air past the Tg of PEI (~217 °C) caused widespread structural damage due to oxidation of the underlying Cu substrate. This conclusion was supported through an in-depth mechanistic investigation of annealing-induced deformation. First, changing the annealing atmosphere to high-purity nitrogen prevented widespread structural deformation from occurring during annealing, regardless of temperature. Second, the onset of film deformation during annealing in air was strongly associated with temperatures above the glass transition temperature of PEI. Finally, Arrhenius analysis yielded an activation energy of 159 kJ/mol for the deformation process, almost twice that associated with Cu oxidation and instead closer in scale to that of glass transitions in amorphous polymers. A physical failure mechanism was proposed based on the in-plane shrinkage of PEI during the glass-to-rubber transition caused by the release of internal stress induced by spin-coating. In-plane contraction of PEI would then cause compression of SLG as internal stress was released, which we confirmed from a significant blue-shift in the 2D band of SLG by ~30 cm-1 after annealing both with and without visible deformation. Importantly, we demonstrate that common secondary processing steps, like thermal annealing, will have critical effects on film properties if conditions are not properly controlled.
The mechanical fatigue and cycling stability of PGL thin films is another topic of interest for developing reliable PGLs with long operational lifetimes. Mechanical failure analysis might be used to evaluate failure mechanisms governing interfacial fatigue in PGL thin films. However, little work has been done understanding mechanical fatigue in PGLs. To this end, we explore the use of mechanical bulge testing for the evaluation of cycling fatigue in PGLs and construct a custom instrument, known as a bulge test apparatus (BTA), to perform fatigue measurements. In general, our BTA test platform provides a means of analyzing different fabrication/design conditions. To test its use, we prepared PEI/SLG thin films with different tensioning weights between 0 and 30 g. Then, the well-established methods for bulge testing were applied to the dynamic loading of PEI/SLG using the BTA. Specifically, the evolution of bulge-test-derived pre-stress in PEI/SLG was monitored as a function of cycle number and tensioning weight, which revealed large fluctuations in pre-stress with mechanical cycling up to ~200k cycles, which was unexpected for these films. To investigate the underlying mechanism, we further employed Raman spectroscopy, optical microscopy, and scanning electron microscopy (SEM) to determine the strain state of SLG before and after cycling and probe for structural changes. Raman measurements revealed that mechanical cycling induced a large redshift in the 2D and G peak positions of SLG by ~25.4 and ~10.1 cm-1, respectively, for 30 g-tensioned PEI/SLG, with similar shifts observed for 20 g-tensioned films. Optical and SEM images showed possible changes in the surface structure of SLG after cycling accompanying the shift in Raman characteristics. We discuss the possibility of interfacial failures involving in-plane slippage and out-of-plane buckling of SLG based on our results. If validated, the use of BTA may provide future insight regarding mechanical fatigue and failure at the PGL interface during dynamic loading. The practical relevance of methods for determining the influence of design and fabrication characteristics in PGLs will no doubt be invaluable for further development. Additional work in this area will be necessary to connect our analytical approach by BTA to underlying failure mechanisms in PGLs. / Doctor of Philosophy / Due to its record-breaking properties, graphene has tremendous promise for use in next-generation consumer electronics, like ultra-thin audio speakers and flexible displays. However, on its own, single-layer graphene (SLG) is not stable enough for practical uses. Therefore, in this dissertation, I construct a framework for developing polymer substrates to stabilize and enhance graphene based on the design and fabrication of polymer/graphene laminates (PGLs). To explore this framework, I design polyetherimide (PEI)/SLG thin films with controlled mechanical properties, evaluate fabrication-induced defects, and develop an analytical approach for measuring mechanical fatigue in these films.
The ability to precisely control thin film mechanics has important implications for the application of PGLs. However, it is challenging in PGL systems to enhance mechanical properties due to the limited amount of graphene that is used. Therefore, I show that the design of PEI/SLG film thickness can effectively control mechanical reinforcement, even at very low loadings of graphene. I further investigate the design of a controlled pre-tensioning in PEI/SLG and show that tensioning can be used to modify the mechanical response. However, using a custom mechanical testing platform, I also determine that mechanical fatigue may increase with pre-tensioning as well.
The impact of fabrication procedures on the properties of PGL thin films is another important aspect of PGL development that is often overlooked. Specifically, thermal annealing may introduce residual contamination and/or structural defects that reduce material properties. Therefore, I present a detailed study of thermal annealing-induced structural failures in PEI/SLG films, which shows that annealing at high temperature induces substrate oxidation and structure damage in the films. The results of this annealing study demonstrate the potential negative effects of fabrication on PGL development. Finally, this dissertation ends by discussing future directions in PGL design and fabrication that will need to be addressed in the coming years for further development of PGL thin film electronics.
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A Study on Mechanical Structure of a MEMS Accelerometer Fabricated by Multi-layer Metal TechnologyYamane, Daisuke, Konishi, Toshifumi, Teranishi, Minami, Chang, Tso-Fu Mark, Chen, Chun-Yi, Toshiyoshi, Hiroshi, Masu, Kazuya, Sone, Masato, Machida, Katsuyuki 22 July 2016 (has links) (PDF)
This paper reports the evaluation results of the mechanical structures of MEMS (micro electro mechanical systems) sensor implemented in the integrated MEMS inertial sensor for a wide sensing range from below 0.1 G to 20 G (1 G = 9.8 m/s^2). To investigate the mechanical tolerance, a maximum target acceleration of 20G was applied to the sub-1G sensor which had the heaviest proof mass of all that sensors had. The structure stability of Ti/Au multi-layered structures was also examined by using Ti/Au micro cantilevers. The results showed that the stoppers effectively functioned to prevent the proof mass and the springs from self-destruction, and that the stability of Ti/Au structures increased with an increase in width. Those results suggest that the proposed stopper and spring structures could be promising to realize MEMS sensors.
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Tillståndsövervakning av järnvägsinfrastruktur : En studie för framtidens sakernas internet-lösningarLindqvist, Jonas January 2017 (has links)
Då komponenter för tillståndsövervakning idag är billiga, små storleksmässigt och kraftfullare än tidigare, kan hårdvara byggas ihop, mjukvara programmeras och sedan appliceras på kritiska delar i ett system, mer kostnadseffektivt och i större omfattning än tidigare. I stor skala kallas detta sakernas internet, och är framtiden för underhållsarbete då personal inte längre behöver vara fysiskt närvarande i samma grad som tidigare. En proprietär lösning kostar idag vanligtvis över 5 000 kr. Detta projekt har behandlat prototyper till en kostnad av cirka 1 000 kr med öppen hårdvara och mjukvara, vilket stödjer affärsutveckling och bidrar till ett bredare spektra av leverantörer, vilket sätter press på marknaden gällande olika lösningar. Syftet med denna studie är att utveckla och testa mätningar i verklig miljö för tillståndsövervakning av utsatta delar av järnvägsinfrastrukturen, som punktfel i spårläge och spårväxlar. Projektet innefattar prototyper, energihantering, loggning av data och hur användbara dessa data är. Sensorerna är av typen MEMS accelerometrar och olika montage av dessa har testats. Målsättningen har varit att utvärdera hur dessa fungerar i verklig miljö och hur användarvänliga dessa är för att mäta rörelse av räls och sliper. Mer specifikt, avser detta fältprov av accelerometer för uppvakning och energihantering, sensor för insamling av vibrationer för rörelse i spår och analys av insamlad mätdata. Fälttest visade att en accelerometerbaserad uppvakningssensor kan väcka ett mätsystem genom vibrationer i rälsen ca: 70 meter innan tåget kommer fram till sensorn. Tydligaste mätdata för analys erhölls vid montage på slipers samt då ett avstånd på ca: 70 meter togs. Montering i direkt närhet till mätobjektet på rälslivet bidrog till en signal med inslag av högfrekventa vibrationer. Då tydlig mätdata erhölls kunde antal boogies och axlar identifieras vilket kunde verifieras med bild på loket. Mätdata som analyserades kunde via integration erhålla förskjutning i vertikal samt lateral riktning. Detta är användbart, både för infrastrukturförvaltare samt för underhållsentreprenörer, då degradering kan upptäckas i god tid och förebyggande underhållsåtgärder kan sättas in mot berörda feltyper. Den önskade livslängden enligt infrastrukturförvaltare var minst fem år, och efter mätning av strömåtgång enligt nuvarande specifikation så uppnås detta om mätningar sker sju gånger dagligen med litiumbatterier (1200 mAh) som strömkälla. Som ett första steg mot sakernas internet så har detta arbete skapat en god grund för att förverkliga detta. Fortsatt arbete efter detta projekt kan innefatta gprs och Wi-Fi för internetuppkoppling samt strömmätning för att se hur mycket förbrukningen ökar. Parallellkoppling av batterier kan vara en lösning för längre livslängd ifall förbrukningen påverkas markant. Olika varianter av filtrering för en tydligare signal kan också vara av intresse. Andra typer av sensorer, både för verifiering av resultat i denna rapport samt för att utprova alternativ. Detta kan innefatta geofoner, multi-depth deflectometers och andra typer av accelerometrar. / Since condition monitoring devices today are cheap, small size and more powerful than before, hardware can be built together, software programmed, and then applied to critical parts of a system, more cost-effective and to a greater extent than before. On a large scale this is called the Internet of Things, and is the future of today's maintenance work, as staff no longer needs to be physically present to the same extent as before. A proprietary solution today generally costs over 5,000 SEK. This project has processed prototypes at a cost of approximately 1,000 SEK with open hardware and software, which supports business development and contributes to a wider range of suppliers, which puts pressure on the market for different solutions. The purpose of this study is to develop and test measurements in real environment for condition monitoring of exposed parts of the railway infrastructure, such as point errors in track and railroad switches. The project includes prototypes, energy management, data logging and how useful these data are. The sensors are of the type MEMS accelerometers and various assemblies of these have been tested. The goal has been to evaluate how these works in a real environment and how user friendly these are to measure the movement of rails and grinders. Field test showed that an accelerometer-based wake-up sensor can wake a measuring system by vibration in the rail approximately 70 meters before the train reaches the sensor. Clearest measurement data for analysis was obtained when mounted on grinders and when a distance of about 70 meters was taken. Mounting in close proximity to the measurement object on the rail life contributed to a signal with high frequency vibration input. When clear measurement data was obtained, the number of boogies and axes could be identified, this could be verified by image on the train. Measurement data analyzed could through integration obtain displacement in vertical as well as lateral direction. This is useful, both for infrastructure managers and for maintenance entrepreneurs, as degradation can be detected in time and preventive maintenance actions can be set against the relevant failure types. The desired lifespan according to infrastructure managers was at least five years, and after measuring current consumption according to the current specification, this is achieved if measurements take place seven times a day with lithium batteries (1200 mAh) as the power source. As a first step towards the Internet of Things, this work has created a good foundation to make this reality. Continued work after this project may include gprs and Wi-Fi for internet connection as well as current measurement to see how much usage is increasing. Parallel coupling of batteries can be a solution for longer service life if consumption is significantly affected. Different variants of filtering for a clearer signal may also be of interest. Other types of sensors, both for verification of results in this report and for testing alternatives. This may include geophones, multi-depth deflectometers and other types of accelerometers
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