Rotary air-to-air energy exchangers (also called energy wheels) transfer both heat and moisture between supply and exhaust airstreams in buildings. In this thesis, it is hypothesized that the transient step response characteristics of an energy wheel are uniquely related to the steady-state cyclic response of the wheel. The primary objective of this research is to study the transient response of a humidity/temperature sensor and measure energy wheel performance with a new test procedure that uses only transient response characteristics. In this thesis, the transient characteristics of a humidity/temperature sensor and an energy wheel to a step change in relative humidity and temperature are investigated through two types of measurements. One test uses a small airflow, at controlled temperature and humidity conditions, passing through a small section of a porous wheel while measuring the outlet conditions after the inlet conditions are suddenly changed. For a step input, it is shown that the outlet humidity/temperature sensor data correlate with an exponential function with two time constants. Since the transient response characteristics of the humidity/temperature sensor must be known to predict the response of the wheel alone, a second test is required that is similar to the first test except that the wheel is removed. This test is used to obtain the transient response of the sensor alone. Data from these tests show that both the sensor and the sensor plus wheel have two sets of two time constants. An analysis is presented to determine the transient response of the wheel alone using the correlated properties of the sensor alone and the sensor with a wheel upstream. The challenge undertaken in this research was the development of a more flexible, lower cost test facility than that presented in ASHRAE Standard 84-1991(Method of Testing Air-to-Air Heat Exchangers). In future work, this new laboratory experimental test facility should be adapted to test most types of energy wheels. The configuration allows a wide range of mass flow rates, inlet supply air temperatures and relative humidities. Uncertainty analysis is used for each transient test for the sensors and air-to-air energy wheels to specify the sensor and wheel plus sensor characteristics. This uncertainty analysis shows that accurate sensor calibration under equilibrium conditions and the start time for the humidity sensor step change is crucial to achieve low uncertainties in the transient behaviour of sensor and energy wheels. Knowing the uncertainty in the characteristics of the sensors and the wheel plus sensors the uncertainty in the transient response of the wheel alone is predicted. The first time constant of the humidity sensor is found to be about 3 seconds, while the second time constant is found to be about 100 seconds. It is found that the predicted response of the wheel alone gives time constants that are about 6 seconds and 140 seconds. Other researchers can use this information presented in this thesis to estimate the effectiveness of an energy wheel.

L'objectif premier de ce projet est la mise au point de procédés de fabrication microélectroniques/microtechnologiques compatibles avec l'utilisation d'un support papier. Pour cela, des techniques comme l'évaporation thermique sous vide, la photolithographie, l'électrodéposition et l'anodisation d'aluminium ont été développées et adaptées à ce support. Des bancs de caractérisations structurels, électriques et flexibles ont été aussi mis en œuvre pour étudier la fiabilité des couches déposées sur un tel substrat. En application, un capteur d'humidité à base d'oxyde d'aluminium flexible a été fabriqué et les tests en humidité ont montré d'excellents résultats permettant de valider le travail effectué. / The primary objective of this project is the implementation of microelectronics/microtechnology processes compatible with the use of paper-based substrate. For this purpose, techniques such as thermal vacuum evaporation, photolithography, electroplating and anodizing aluminum have been developed and adapted to this substrate. Structural, electrical and flexible characterizations benches have also been implemented to study the reliability of the layers deposited on such substrate. A moisture sensor based on flexible aluminum oxide was made and humidity tests have shown excellent results which validate the work.

This thesis deals with the automation of transport experiments on graphene using the graphical programming language LabVIEW. Specifically, the experiments with graphene relative humidity sensors are based on: a two-point graphene structure, a two-point structure of SiO$_2$ and a four-point graphene structure in the form of a Hall bar. In all of these experiments, relative humidity, input electrical parameters, SPM measurements, and macroscopic transport properties are measured simultaneously. The program DeviceManager developed in framework of this thesis simplifies the implementation of these experiments.

The purpose of this project is to build a wireless sensor network for measuring temperature and relative humidity in hop drying facility. This is a monitoring device, consists of several sensor units and one control and display unit. Display unit coordinates a whole network and can display data on LCD or download collected data to PC. Sensor unit measures a relative humidity, temperature, battery voltage and transmits data to display unit. Units contain a transceiver which operates in ISM band 868 MHz. Circuits are driven by 8-bits microcontroller Freescale.

First part of this work is focused on the description exist methods for measuring refraction index of air. Second part deal with concrete problem realization measurement unit for monitoring of refraction index of air. Refraction index of air is measured indirect method which is based on a modified Edlen formula.

The thesis deals with preparation of graphene nanostructures and their applications in the measurement of transport properties of graphene. The contacts for measurement of resistance are fabricated by electron beam lithography on graphene exfoliated flakes, CVD graphene layers and grains. Graphene is also shaped using the same method. Resistivity of the layer, concentration and mobility of charge carriers are determined by different approaches. Hysteresis appearing in dependence of resistivity on the gate voltage is discussed as well. A significant part of the work is dedicated to monitoring the response of graphene resistance to relative humidity changes and potential use of graphene as a sensor of relative humidity.

The increasing demand for digitalization has spurred the need for novel and sustainable designs of electronic devices like sensors. Advanced additive print technologies, organic inks, and bio-based substrates in device fabrication exhibit promising potential for reducing energy and raw material consumption, thereby alleviating environmental impacts. One such innovation is the novel method of laser graphitization in designing devices like printed humidity sensors. This study focuses on evaluating the environmental impacts of implementing this novel technique in the field of printed electronics. In particular, the thesis conducts a cradle-to-gate life cycle assessment (LCA) of producing a resistive-type humidity sensor from a forest-based wood ink using laser graphitization. The sensor is based on the design that was demonstrated in the lab facilities at the Research Institutes of Sweden (RISE), Norrköping. The assessment is at a lab-scale production of making 1mm2 area of a laser-induced graphitized (LIG) sensor, excluding usage, disposal, or recycling phases. The results highlight impacts from electricity usage as the primary contributor to the overall environmental impacts, across the production process, followed by the impacts from material usage. The impact share distribution from these two hotspots identifies opportunities in the process that need to be prioritized for immediate actions. Sensitivity analyses varying the sensor layer thickness and the electricity mix of the laboratory facilities reveal insightful impact trends. The results from scenario analyses show the LIG sensor to have much lower environmental impacts than that of a sensor with silver electrodes and carbon-based sensing ink. They also show potential for achieving economies of scale from the mass production of LIG sensors. The data inventory for the processes and components of the sensor stands as a crucial part of this study, relying heavily on literature, assumptions, and proxy data. While these may reveal some uncertainties and limitations, the study nonetheless, serves as an important reference for future research concerning similar databases and a cradle-to-grave LCA of the sensor. / Den ökade efterfrågan för digitalisering har skapat behov av nya och hållbara designs av elektroniska enheter som sensorer. Avancerade lager printteknologier, organiskt bläck och biobaserat substrat i enhetstillverkning visar lovande potential för att reducera energi och rå materielkonsumtion och därmed minskning av miljöpåverkan. En sådan innovation är den nya metoden av lasergrafitisering i designenheter som printad fuktighetssensor. Denna studie har som fokus att utvärdera miljöpåverkan av ny teknik inom området tryckt elektronik. I synnerhet ska avhandlingen göra en livscykelanalys (LCA), från råvaruutvinning till slutprodukt av att producera en resistent fuktsensor från ett skogsbaserat träbläck genom lasergrafitisering. Sensorn är baserad på en design som var demonstrerad i en labbanläggning hos forskningsinstitutet RISE i Norrköping. Forskningen är analysen av laboratorieskalad produktion av 1mm2 lasergrafitiserad sensoryta, exklusive användning, bortskaffande och återvinningsfaser. Resultaten lyfter fram påverkan från elektronisk användning som den primära bidragaren till övergripande miljöpåverkan över hela produktionsprocessen, följd av påverkan från materiell användning. Påverkan från dessa två hotspots uppmärksamgör möjligheter i processen som är av prioritet för omedelbart åtgärdande. Känslighetsanalyser av de varierande sensorskiktens tjockhet och elektronisk mix i laboratoriums faciliteten, påvisar insiktsfulla påverkanstrender. Resultaten från scenarioanalyser visar att LIG sensorer har mycket lägre miljöpåverkan än sensorer med silverelektroner och kolbaserat avläsningsbläck. De visar också potential för att uppnå ekonomisk skalbarhet för massproducering av LIG-sensorer. Datalagring för processerna och komponenterna av sensorn står som kritisk del av studien, med en tung tillit på litteratur, antaganden och proxydata. Då dessa faktorer kan påvisa några osäkerheter och begränsningar så bidrar studien ändå som en viktig referens för framtida forskning berörande liknande databaser och en LCA från råvaruutvinning till sluthanteringsfasen av sensorn.

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This thesis deals with creating hardware and software equipment of intelligent beehive for data collection purpose. Measurement characteristics are temperature, humidity, weight of beehive and audio record of bees. They are measured by available IoT technology. They are simple single-chip component with a clear focus. This thesis also include creation of software for measurements this characteristics and communications with server. The software featured of the remote server are also documented. This software analyze incoming measurement and also provides their displays. Software in this thesis is developed in language Python.

This thesis compares the methods for the determination of air and moisture condensation in the construction. There are descriptions of the various methods and formulas for measuring humidity and methods for the calculation of condensation in building structures. The practical part describes the development of a method for verifying the condensation of moisture in construction. Parts of this work are the materials and methods for the development of the humidity sensor. There were used two methods – capacitive and resistive for measuring moisture condensation. In the conclusion is the evaluation of the humidity sensor and compares the results of individual measurements.