Electronically monitoring whether or not your car block heater is connected to a mains outlet might at first seem like an arbitrary task. A device installed in the comfort of the car seating area, which tells the user at every startup whether or not his/her car is connected to a mains outlet, could have market appeal though. But in order for it to be a worthwhile idea to pursuit, a certain requirement has to be met. It has to be able to be able to accurately detect whether or not the car is connected, through a single connection; the car ground. A certain part of the voltage in the phase of the mains will be capacitively coupled upon the safety ground. By exploiting the fact that the car ground will be connected to the mains safety ground when the block heater cable is in use, a device which can detect that coupled voltage could possibly be developed. In other words, a cable monitoring unit which in actuality detects a connection to the mains safety ground through capacitive coupling, hence the title of this dissertation. This work sets out to taking appropriate measurements to find out whether or not this proposed method of safety ground detection is valid, with heavy emphasis on whether or not it is applicable to a cable monitoring unit. According to the measurement results, an appropriate device is developed. A device which can fill the function described in the previous paragraph. Development of such a device involves; proper method of supplying power which upholds a galvanically isolated floating ground, signal processing, reliable detection mechanism, and considerations to how unintentional capacitive coupling behaves. A theoretical model of the device is put forth, as well as an actual rough prototype to in practice try to prove that the concept and method is valid. Downsides and problems with the device are discussed, such as upholding an effective detection system without making the device hard and cumbersome to use. Possible solutions to these problems are also proposed. The possible future of the concept of this device is also touched upon.

This research presents a novel capacitive-sensing-based method to measure fluid velocity for microfluidics devices. To illustrate the importance of fluid velocity measurement, a case study was first conducted for a split and recombine micromixer. The study underscored the influence of fluid velocity on micromixer efficiency and mixing quality. The proposed fluid velocity measurement method employs two capacitance sensing electrodes placed along the fluid channel, capable of detecting small capacitance changes as fluid passing through the sensing area. The relation between capacitance changes and fluid velocity in the proposed sensing structures was developed and hence used to estimate fluid velocity. The proposed technique does not require extensive bench equipment and is suitable for point-of-care applications. To validate our approach, we implemented a two-step 3D printing process, creating a Polylactic acid (PLA) micro platform with embedded graphene–PLA composite electrodes. The accuracy of the developed method was investigated by cross-verifying the obtained velocities with an optical measurement method. Most absolute percentage discrepancies between the results from the proposed method and the optical method are under 12%, validating the precision of the proposed method. Future research will focus on integrating this velocity measurement method into microfluidic devices produced using advanced microfabrication technologies.

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Musik-applikationen c3n play används på surfplattor och mobiltelefoner som har den kapacitiva pekskärmstypen. I dagsläget kan musik-applikationen enbart styras med fingrarna. Spelpjäser, utvecklades för att målgruppen skulle kunna kombinera fingerinmatning med något fysiskt och för att underlätta spelandet. En konvergerande produktutvecklingsprocess innefattande faser och aktiviteter tillämpades. Inledningsvis genomfördes en detaljerad informationsinsamling som grund för det fortsatta arbetet. Analys av konkurrenternas produkter och en benchmarking implementerades, för att både identifiera kraven som ställts på produkten och upprätta en kravspecifikation. Spelpjäsen delades in i tre delar: formen på hela spelpjäsen, mönster som gör att användarna kan identifiera varje spelpjäs och mönster på undersidan som programvaran kunde identifiera. Därefter genererades flera idéer på formen av spelpjäsen, vilka utvärderades med hänsyn till de uppsatta kraven. Idéer som ansågs uppfylla kraven bäst gick vidare till konceptgenereringsfasen, där fem olika förslag kunde visualiseras i skisser och CAD-modeller (Computer Aidid Design). Koncepten utvärderades och förbättrades för att tillfredsställa användarnas behov och förväntningar. Det slutliga konceptet på formen gjordes i fyra olika varianter, vilka framställdes som prototyper för vidare test av målgruppen. Konceptlösningar på spelpjäsens identifieringsmönster av användaren analyserades för att passa in i c3n play-användargränssnitten. Tekniken för att identifiera spelpjäsen mot den kapacitiva pekskärmstypen utvecklades via tester, där avstånd och vinklar på kontaktpunkterna bestämdes. Viktiga produktutvecklingsverktyg implementerades för att säkerställa såväl spelpjäsernas hållbarhet som miljövänlighet, med hänsyn till produktlivscykel, tillverkning, montering och tillförlitlighet samt kostnadsmedvetenhet. Därefter valdes lämpliga material samt en lämplig tillverkningsmetod. Detta resulterade i en produktfamilj bestående av åtta stycken spelpjäser som ändrar på var sin funktion i c3n play-applikationen. En spelpjäs som förändrar amplitud, resonans, högtpassfilter, lågt-passfilter, delay, zoom + pan, kompression och feedback. / The application c3n play can be used on tablets and mobile phones that have capacitive multi touchscreens. The application can only be controlled by using the finger input. Tangible user interface was developed so the target group can use something physically “checkers” in a combination with the finger input. A product development process comprising phases and activities was implemented. Initially a detailed information collection were conducted and used as underlying to the continued work. Competitors’ products were analyzed and a benchmarking was implemented to identify user needs and to be able to make a target specification. Checkers was divided in three parts, shape of the whole checker, pattern so users can identify every checker and a pattern on the bottom so the software can identify the checkers on the screen. After that ideas were generated and the shape of the checker was evaluated. Ideas that was considered to meet the user needs went on to concept generation phase, where five different proposals was visualized in sketches and CAD (Computer Aided Design) - models. Concepts was evaluated and improved to satisfy customer needs and expectations. Final concept of the shape was developed into four different variants that was prepared as prototypes for further testing by target group. Concept solutions on identification pattern was analyzed to fit c3n play user interface. Technology to identify the checker against capacitive screen was developed by tests. Where distance and angles of contact points was determined. Important product development tools was implemented to ensure the checkers sustainability. With respect to the product life cycle, environment, manufacturing, assembly, reliability and cost consciousness. Suitable materials and manufacturing method was then chosen. Resulted in a product family consisted of eight different checkers. Each checker can change a different function in the c3n play-application. Amplitude, Resonance, Highpassfilter, Low-passfilter, Delay, Zoom + Pan, Compression and Feedback.

<p><p>This project aims in building a new experimental setup for capacitive measurements of a pH-Sensor. PAA-IOA (Poly Acrylic Acid co – Iso Octyl Acrylate) is the dielectric material over the in-plane interdigitated gold electrodes where PAA IOA acts as an H⁺ ion sensing layer. The changes in the capacitance of the sensor when the sensor is dipped into different pH solutions will be quantized accordingly. The dipping setup is built in such a way that the electrodes (containing the polymer layer) can be easily dipped into different pH liquids and to eliminate any contact between the polymer and set-up (e.g. pressure effects on the sensor). From the setup it is visible that the gold electrodes are not subjected to any external force as in the case of the setup used previously. Three phases of experiments have been used in this project to get a clear view on the working principle of the polymer. The effect of pH is only considered in this project, as we already have the evidences for the salt sensitiveness of PAA IOA from the work done in the past. The influence of various pH on polymer is observed as capacitance measurements. Response time is more than 5 minutes for PAA IOA. ∆C decreases with frequency and frequency choice depends on application/electronics. The degree of other ions influence is not clear but they have a minor influence in the resistance.</p></p>

This project aims in building a new experimental setup for capacitive measurements of a pH-Sensor. PAA-IOA (Poly Acrylic Acid co – Iso Octyl Acrylate) is the dielectric material over the in-plane interdigitated gold electrodes where PAA IOA acts as an H+ ion sensing layer. The changes in the capacitance of the sensor when the sensor is dipped into different pH solutions will be quantized accordingly. The dipping setup is built in such a way that the electrodes (containing the polymer layer) can be easily dipped into different pH liquids and to eliminate any contact between the polymer and set-up (e.g. pressure effects on the sensor). From the setup it is visible that the gold electrodes are not subjected to any external force as in the case of the setup used previously. Three phases of experiments have been used in this project to get a clear view on the working principle of the polymer. The effect of pH is only considered in this project, as we already have the evidences for the salt sensitiveness of PAA IOA from the work done in the past. The influence of various pH on polymer is observed as capacitance measurements. Response time is more than 5 minutes for PAA IOA. ∆C decreases with frequency and frequency choice depends on application/electronics. The degree of other ions influence is not clear but they have a minor influence in the resistance.

No description available.