MEMS Accelerometers are broadly used in the area of vibration sensor. Their applications range from seismic disturbances, to automotive industry such as airbag systems, active suspension, and smart braking. Traditionally, the acceleration is detected electrically by measuring either capacitive variations or piezoelectric signals. Those approaches suffer from a number of drawbacks, such as low sensitivity due to low signal-to-noise ratio (SNR), small dynamic range, high temperature sensitivity, etc. In this thesis, a MEMS-based optical accelerometer is designed and analyzed. The device can be fabricated on a silicon-on-insulator (SOI) wafer, on which a double-leg single-mode optical rib waveguide is used to propagate 1.55μm laser beam. The device integrates the waveguide with a mechanical oscillator, and is able to detect in-plane vibrations of the oscillator by taking advantages of optical interference. According to the analysis, the maximum working range of the oscillator can be as large as 50μm and the acceleration sensitivity can be below 1μg/Hz¹/². Device fabrication and characterization are also carried out and described in the thesis. All necessary fabrication steps and details as well as characterization setups are given. Due to several fabrication challenges in UBC (e.g. malfunctioned equipment), a complete device has not been fabricated. More fabrication and characterizations are to be continued as future work.

Today digital TV receivers (Set-Top-Boxes) are mainly controlled by IR-based remote control units (RCUs). With new services emerging in thereceivers where better browsing and pointing abilities are desirable (VODservices, Web services, games etc), one solution is a new type of RF remotecontrol. An RF RCU has a number of advantages, e.g. when in range, ithas 100% reliable transmission, it is not sensitive to direction, and it doesnot require a free way to the receiver (i.e. it allows the receiver to be hiddenbehind the TV-set or in a cabinet).

This thesis mainly focuses on sensor nodes design. A small two-axis and three-axis accelerometer using optic fiber with FBG written in the core as sensing element were originally designed due to the advantages of FBG mentioned above. The proposed design has a concentrated mass sitting in the middle of a rigid frame, and a glass fiber with a FBG written in the fiber core as a stiff spring is connected between each side of the frame and the mass. The two accelerometers can decouple the ground motion along different axes, resulting in virtually zero cross-sensitivity, which exceeds currently available seismometers. The accelerometer or seismometer has a working bandwidth below the structure’s natural frequency and linearly responds to ground movement. COMSOL Multiphysics by using Finite Element Method (FEM) was used to analyze and simulate the two devices.

MEMS Accelerometers are broadly used in the area of vibration sensor. Their applications range from seismic disturbances, to automotive industry such as airbag systems, active suspension, and smart braking. Traditionally, the acceleration is detected electrically by measuring either capacitive variations or piezoelectric signals. Those approaches suffer from a number of drawbacks, such as low sensitivity due to low signal-to-noise ratio (SNR), small dynamic range, high temperature sensitivity, etc. In this thesis, a MEMS-based optical accelerometer is designed and analyzed. The device can be fabricated on a silicon-on-insulator (SOI) wafer, on which a double-leg single-mode optical rib waveguide is used to propagate 1.55μm laser beam. The device integrates the waveguide with a mechanical oscillator, and is able to detect in-plane vibrations of the oscillator by taking advantages of optical interference. According to the analysis, the maximum working range of the oscillator can be as large as 50μm and the acceleration sensitivity can be below 1μg/Hz¹/². Device fabrication and characterization are also carried out and described in the thesis. All necessary fabrication steps and details as well as characterization setups are given. Due to several fabrication challenges in UBC (e.g. malfunctioned equipment), a complete device has not been fabricated. More fabrication and characterizations are to be continued as future work.

MEMS Accelerometers are broadly used in the area of vibration sensor. Their applications range from seismic disturbances, to automotive industry such as airbag systems, active suspension, and smart braking. Traditionally, the acceleration is detected electrically by measuring either capacitive variations or piezoelectric signals. Those approaches suffer from a number of drawbacks, such as low sensitivity due to low signal-to-noise ratio (SNR), small dynamic range, high temperature sensitivity, etc. In this thesis, a MEMS-based optical accelerometer is designed and analyzed. The device can be fabricated on a silicon-on-insulator (SOI) wafer, on which a double-leg single-mode optical rib waveguide is used to propagate 1.55μm laser beam. The device integrates the waveguide with a mechanical oscillator, and is able to detect in-plane vibrations of the oscillator by taking advantages of optical interference. According to the analysis, the maximum working range of the oscillator can be as large as 50μm and the acceleration sensitivity can be below 1μg/Hz¹/². Device fabrication and characterization are also carried out and described in the thesis. All necessary fabrication steps and details as well as characterization setups are given. Due to several fabrication challenges in UBC (e.g. malfunctioned equipment), a complete device has not been fabricated. More fabrication and characterizations are to be continued as future work. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

This thesis presents a detailed SIMULINK model for a conventional capacitive &amp / #931 / -&amp / #916 / accelerometer system consisting of a MEMS accelerometer, closed-loop readout electronics, and signal processing units (e.g. decimation filters). By using this model, it is possible to estimate the performance of the full accelerometer system including individual noise components, operation range, open loop sensitivity, scale factor, etc. The developed model has been verified through test results using a capacitive MEMS accelerometer, full-custom designed readout electronics, and signal processing unit implemented on a FPGA. Conventional accelerometer system with force-feedback is used in this thesis. The sensor is a typical capacitive lateral accelerometer. The readout electronics form a 2nd order electromechanical &amp / #931 / -&amp / #916 / modulator together with the accelerometer, and provide a single-bit PDM output, which is decimated and filtered with a signal processing unit, software implemented on a FPGA. The whole system is modeled in MATLAB-SIMULINK since it has both mechanical and electrical parts. To verify the model, two accelerometer systems are implemented. Each accelerometer system is composed of a MEMS accelerometer, readout circuit, and decimation filters. These two different designs are implemented and simulation and test results are compared in terms of output noise, operational range, open loop sensitivity, and scale factor. The first design operates at 500 kHz sampling rate and has 0.48 V/g open-loop sensitivity, 58.7 &micro / g/&amp / #8730 / Hz resolution, &plusmn / 12g operation range, and 0.97*10-6 g/(output units) scale factor, where these numbers are in close agreement with the estimated results found with simulations. Similarly, the second design operates at 500 kHz sampling rate and has 0.45 V/g open-loop sensitivity, 373.3 &micro / g/&amp / #8730 / Hz resolution, &plusmn / 31g operation range, and 2.933*10-6 g/(output units) scale factor, where these numbers are also close to the estimated results found with simulations. Within this thesis study, an accelerometer sensing element design algorithm is also proposed which is based on the theoretical background obtained in accelerometer system SIMULINK model. This algorithm takes the requirements of the desired accelerometer as input and outputs the dimensions of the minimum noise accelerometer satisfying these requirements. The algorithm is extended to design three different accelerometer structures. An accelerometer sensing element is designed using the proposed design algorithm and tested in order to see performance matching of the algorithm. The designed accelerometer has &plusmn / 33.02g operational range and 155&micro / g/&amp / #8730 / Hz noise where these numbers matches with the values found by the algorithm

abstract: The applications which use MEMS accelerometer have been on rise and many new fields which are using the MEMS devices have been on rise. The industry is trying to reduce the cost of production of these MEMS devices. These devices are manufactured using micromachining and the interface circuitry is manufactured using CMOS and the final product is integrated on to a single chip. Amount spent on testing of the MEMS devices make up a considerable share of the total final cost of the device. In order to save the cost and time spent on testing, researchers have been trying to develop different methodologies. At present, MEMS devices are tested using mechanical stimuli to measure the device parameters and for calibration the device. This testing is necessary since the MEMS process is not a very well controlled process unlike CMOS. This is done using an ATE and the cost of using ATE (automatic testing equipment) contribute to 30-40% of the devices final cost. This thesis proposes an architecture which can use an Electrical Signal to stimulate the MEMS device and use the data from the MEMS response in approximating the calibration coefficients efficiently. As a proof of concept, we have designed a BIST (Built-in self-test) circuit for MEMS accelerometer. The BIST has an electrical stimulus generator, Capacitance-to-voltage converter, ∑ ∆ ADC. This thesis explains in detail the design of the Electrical stimulus generator. We have also designed a technique to correlate the parameters obtained from electrical stimuli to those obtained by mechanical stimuli. This method is cost effective since the additional circuitry needed to implement BIST is less since the technique utilizes most of the existing standard readout circuitry already present. / Dissertation/Thesis / M.S. Electrical Engineering 2014

Temporal trend research in some components of health-related physical fitness and activity among young people is lacking. However, the increasing prevalence of overweight and obesity in young people over the last couple decades has created speculation of secular deterioration in health-related physical fitness and activity. In an effort to address the speculation, this research project compared health-related physical fitness and activity between two groups of children: Old Order Mennonite children in southwestern Ontario (n = 124; aged 9.1 to 13.8 years), who live an agrarian lifestyle which does not include motorized transportation, computer use, or television viewing and rural children in central Saskatchewan (n = 165; aged 8.8 to 13.2 years), who live a contemporary Canadian lifestyle. The Canadian Physical Activity, Fitness, and Lifestyle Appraisal (CPAFLA) was used to measure health-related physical fitness. The CPAFLA is a battery of tests measuring anthropometry (standing height, body mass, skinfolds, and waist girth), cardiorespiratory endurance (step test), and musculoskeletal fitness (handgrip strength, push-ups, partial curl-ups, and trunk forward flexion). Physical activity was measured on seven consecutive days using the Model AM7164 activity monitor. The Physical Activity Questionnaire for Older Children (PAQ-C) was also employed. The PAQ-C is a guided, self-administered seven-day recall questionnaire, which assesses general levels of physical activity in schoolchildren of grades four to eight during the school year. With biological age as a covariate, univariate and multivariate analyses of covariance were used to compare health-related physical fitness and activity between groups respectively. Old Order Mennonite children evinced greater mean handgrip strength (p < 0.0001) and rural Saskatchewan children demonstrated greater mean trunk forward flexion (p < 0.001). However, there were no significant differences between groups in the other health-related physical fitness variables. Old Order Mennonite children had significantly greater mean activity counts·min-1 (p < 0.001), mean activity counts·day-1 (p < 0.0001), and mean minutes of moderate physical activity·day-1 (p < 0.0001). Collectively, these results suggest that Old Order Mennonite children have greater static strength and are more physically active than rural Saskatchewan children. Assuming that Old Order Mennonite children represent Canadian children from previous generations, these results may lend support to secular deterioration in some aspects of health-related physical fitness and activity among Canadian children.

Temporal trend research in some components of health-related physical fitness and activity among young people is lacking. However, the increasing prevalence of overweight and obesity in young people over the last couple decades has created speculation of secular deterioration in health-related physical fitness and activity. In an effort to address the speculation, this research project compared health-related physical fitness and activity between two groups of children: Old Order Mennonite children in southwestern Ontario (n = 124; aged 9.1 to 13.8 years), who live an agrarian lifestyle which does not include motorized transportation, computer use, or television viewing and rural children in central Saskatchewan (n = 165; aged 8.8 to 13.2 years), who live a contemporary Canadian lifestyle. The Canadian Physical Activity, Fitness, and Lifestyle Appraisal (CPAFLA) was used to measure health-related physical fitness. The CPAFLA is a battery of tests measuring anthropometry (standing height, body mass, skinfolds, and waist girth), cardiorespiratory endurance (step test), and musculoskeletal fitness (handgrip strength, push-ups, partial curl-ups, and trunk forward flexion). Physical activity was measured on seven consecutive days using the Model AM7164 activity monitor. The Physical Activity Questionnaire for Older Children (PAQ-C) was also employed. The PAQ-C is a guided, self-administered seven-day recall questionnaire, which assesses general levels of physical activity in schoolchildren of grades four to eight during the school year. With biological age as a covariate, univariate and multivariate analyses of covariance were used to compare health-related physical fitness and activity between groups respectively. Old Order Mennonite children evinced greater mean handgrip strength (p < 0.0001) and rural Saskatchewan children demonstrated greater mean trunk forward flexion (p < 0.001). However, there were no significant differences between groups in the other health-related physical fitness variables. Old Order Mennonite children had significantly greater mean activity counts·min-1 (p < 0.001), mean activity counts·day-1 (p < 0.0001), and mean minutes of moderate physical activity·day-1 (p < 0.0001). Collectively, these results suggest that Old Order Mennonite children have greater static strength and are more physically active than rural Saskatchewan children. Assuming that Old Order Mennonite children represent Canadian children from previous generations, these results may lend support to secular deterioration in some aspects of health-related physical fitness and activity among Canadian children.

Syfte: Syftet är att undersöka validiteten gällande hur väl accelerometern klassificerar mätningar vid 5 sekunders epok.  Metod: Ett total av 13 barn i åldrarna 3-5 år inkluderades i studien som genomfördes med accelerometer GT1M och observation med hjälp av observationsprotokollet CARS. Varje barn hade på sig accelerometern i totalt 55 minuter och observerades samtidigt. Detta för att sen jämföra om accelerometern klassificerar samma beteende som observatörerna observerar. Beteendena var indelade i 4 klassificeringar: stillasittande, låg fysisk aktivitet, moderat fysisk aktivitet och kraftig fysisk aktivitet. Den fysiska aktiviteten/inaktiviteten var uppskattad efter 5 olika forskares skärningspunkter: Freedson (FR), Puyau (PU), Treuth (TR), Mattocks (MT) och Evenson (EV). Sensitivitet (SE) och specificitet (SP) beräknades på de olika skärningspunkterna.  Resultat: FR och EV var de som stämde bäst överrens med CARS vid alla 4 intensitetsnivåerna men inte tillräckligt för att säga att accelerometern mäter det den avser att mäta vid de här skärningspunkterna. De andra FR, PU och TR klassificerade stillasittande som stillasittande men precis som de två skärningspunkterna ovan var de sämre på att klassificera de andra 3 intensitetsnivåerna.   Konklusion: Accelerometern är bra på att klassificera intensitetsnivån stillasittande men vad gällande de andra intensitetsnivåerna; stående med rörelse, moderat fysisk aktivitet och kraftig fysisk aktivitet var accelerometern sämre på att klassificera det som rätt beteende vid 5 sekunders epok i förhållande till CARS-protokollet. Accelerometern och CARS är inte två metoder som fungerar att använda tillsammans utifrån valda skärningspunkter.