A sigma-delta interface built-in self-test and calibration for microelectromechanical system accelerometer's utilizing interpolation method

This work presents the capacitive micromechanical accelerometer with a completely differential high-order switched capacitor sigma-delta modulator interface. Such modulation interface circuit generates one-bit output data using a third sigma-delta modulator low-noise front-end, doing away with the requirement for a second enhanced converter of resolution to encode the feedback route analog signal. A capacitive micromechanical sensor unit with just a greater quality factor has been specifically employed to give greater resolution. The closed-loop and electrical correction control are used to dampen the high-Q values to get the system's stability with high-order. This microelectromechanical system (MEMS) capacitive accelerometer was calibrated using a lookup table and Akima interpolation to find manufacturing flaws by recalculating voltage levels for the test electrodes. To determine the proper electrode voltages for fault compensation, COMSOL software simulates a number of defects upon that spring as well as the fingers of the sensor system. When it comes time for the feedback phase of a proof mass displacement correction, these values are subsequently placed in the lookup table

High Sensitive MEMS Intraocular Capacitive Pressure Sensor (Glaucoma)

الأنظمة الميكانيكية الكهرو ميكانيكية الدقيقة(MEMS) هي تقنية صغيرة الحجم تم تبنيها بشكل كبير من قبل صناعة الدوائر المتكاملة (IC) وتطبيقها على تصغير جميع الأنظمة (الأنظمة الكهربائية والميكانيكية والضوئية والموائع والمغناطيسية وغيرها). تم تحقيق الحد الأدنى من خلال عمليات التصنيع الصغيرة. مستشعر الضغط السعوي هو ببساطة جهاز من نوع الحجاب الحاجز يتم فيه تحديد إزاحة الحجاب الحاجز عن طريق قياس تغير السعة بين الحجاب الحاجز ولوحة معدنية قريبة منه. لهذا الغرض، وأجهزة استشعار الضغط داخل العين مهمة في الكشف عن وعلاج مرض عضال يسمى الجلوكوما. لتحسين حساسية مستشعر الضغط بالسعة، يتم استخدام مادة البولي سيلكون منخفضة التوتر المخدر كمادة متوافقة حيويا. الجلوكوما هو مجموعة من أمراض العيون التي تحدث بسبب ارتفاع ضغط العين (IOP). IOP هو الضغط الذي يمارسه سائل العين يسمى الفكاهة المائية (السائل الواضح داخل العين) الذي يملأ الغرفة الأمامية للعين تظهر النتائج العلاقة المحاكاة بين السعة والضغط لـ ++ clamped silicon وpolysilicon. يمكن أن نرى من الشكل أن السعة الأولية لسيليكون p ++ المشكل هي حوالي 1.81 pF تتراوح السعة من 1.81 إلى 2.162 pF للسليكون p ++ المشدد والحجاب الحاجز polysilicon، على التوالي وبالتالي فإن التغير الكلي للسعة. هذه النتيجة تبين استخدام مادة البولي سيليكون في الحجاب الحاجز حساسية عالية من السيليكون p + +.Micro Electro Mechanical Systems (MEMS) are a small-scale technology that was largely adopted by the IC industry and applied to miniaturize of all systems (electrical systems, mechanical, optical, fluidic, magnetic, etc.). Minimization has been accomplished with small manufacturing processes. A Capacitive pressure sensor is simply a diaphragm-type device in which the diaphragm displacement is determined by measuring the capacitance change between the diaphragm and a metal plate that is close to it. For this purpose, intraocular pressure sensors are important in detection and treatment of an incurable disease called glaucoma. To improve the sensitivity of the capacitive pressure sensor, low stress doped polysilicon material is used as a biocompatible material. Glaucoma is a group of eye diseases that occurs by high intraocular pressure (IOP). IOP is the pressure exerted by the ocular fluid called aqueous humor (the clear fluid inside the eye) that fills the anterior chamber of the eye The results Shows the simulated relation between capacitance and pressure for clamped ++silicon and polysilicon clamped. It can be seen from figure that the initial capacitance for clamped p++ silicon is about 1.81 pF the capacitance varies from 1.81 to 2.162 pF for clamped p++silicon and clamped polysilicon diaphragm, respectively, so the total variation of the capacitance. This result shows the use of poly silicon material in diaphragm is high sensitivity than the p++ silicon

Four dimensional hyperchaotic communication system based on dynamic feedback synchronization technique for image encryption systems

This paper presents the design and simulation of a hyperchaotic communication system based on four dimensions (4D) Lorenz generator. The synchronization technique that used between the master/transmitter and the slave/receiver is based on dynamic feedback modulation technique (DFM). The mismatch error between the master dynamics and slave dynamics are calculated continuously to maintain the sync process. The information signal (binary image) is masked (encrypted) by the hyperchaotic sample x of Lorenz generator. The design and simulation of the overall system are carried out using MATLAB Simulink software. The simulation results prove that the system is suitable for securing the plain-data, in particular the image data with a size of 128×128 pixels within 0.1 second required for encryption, and decryption in the presence of the channel noise. The decryption results for gray and colored images show that the system can accurately decipher the ciphered image, but with low level distortion in the image pixels due to the channel noise. These results make the proposed cryptosystem suitable for real time secure communications

A housekeeping prognostic health management framework for microfluidic systems

Micro-Electro-Mechanical Systems (MEMS) and Microfluidics are becoming popular solutions for sensing, diagnostics and control applications. Reliability and validation of function is of increasing importance in the majority of these applications. On-line testing strategies for these devices have the potential to provide real-time condition monitoring information. It is shown that this information can be used to diagnose and prognose the health of the device. This information can also be used to provide an early failure warning system by predicting the remaining useful life. Diagnostic and prognostic outcomes can also be leveraged to improve the reliability, dependability and availability of these devices. This work has delivered a methodology for a “lightweight” prognostics solution for a microfluidic device based on real-time diagnostics. An oscillation based test methodology is used to extract diagnostic information that is processed using a Linear Discriminant Analysis based classifier. This enables the identification of current health based on pre-defined health levels. As the deteriorating device is periodically classified, the rate at which the device degrades is used to predict the devices remaining useful life

Three-Axes Mems Calibration Using Kalman Filter and Delaunay Triangulation Algorithm

MEMS-IMUs are widely used in research, industry, and commerce. A proper calibration technique must reduce their innate errors. In this study, a turntable-based IMU calibration approach was presented. Parameters such as the bias, lever arm, and scale factor, in addition to misalignment, are included in the general nonlinear model of the IMU output. Accelerometer error parameters were estimated using the transformed unscented Kalman filter (TUKF) with triangulation algorithm is suggested for calibrating inertial measurement unit (MPU6050) three-axes accelerometer. In contrast to the present methods, the suggested method uses the gravitational signal as a constant reference and necessitates no external equipment. The technique requires that the sensor be positioned in a rough orientation and that basic rotations be adopted. This technology also offers a quicker and easier calibration. Comparing the experimental findings with other works, Allan deviation shows significant improvements for the bias instability, where a bias instability of (0.116 μg) is achieved at temperatures between (−15°C) and (80°C)

An oscillation-based technique for degradation monitoring of sensing and actuation electrodes within microfluidic systems.

There is significant interest in the use of electrodes for sensing or actuation in bio-fluidic microsystems. Within these systems high levels of reliability are crucial and complimented by requirements for extremely low probabilities of false positive and false negatives. This paper extends previous work on impedance and oscillation based condition monitoring of electrode arrays by investigating the application of oscillation built-in self-test to microfluidic based electrodes for conductance measurements and a system level implementation for monitoring multiple electrodes on-line

An on-line monitoring technique for electrode degradation in bio-fluidic microsystems.

This paper presents a solution for detecting degradation in electrodes that interface to fluidic or biological systems that forms the basis of numerous actuation and sensing mechanisms in the bio-fluidics field. In this solution, a mid-frequency oscillation test strategy is proposed and evaluated experimentally on an array of electrodes. This technique is based on the sensitivity of the bio-fluidic interface capacitance to degradation, contamination and fouling

Scanning the strength of a test signal to monitor electrode degradation within bio-fluidic microsystems

Lab-on-Chip devices are complex multifunctional heterogeneous microsystems that have the potential to strongly influence advances in important areas such as pharmacology, security, and environmental analysis. High reliability requirements in many of these microsystems are crucial which makes test more challenging especially given the need to validate multiple multi-domain interfaces and realise on-line solutions. Based on fault modeling and impedance analysis of the electrode/electrolyte interface and a customised prototype array structure, this paper proposes a self-test solution that targets degraded sensing microelectrodes within Multi Electrode Array's (MEA). The principle of this approach is to scan the strength of a test signal over the whole array to monitor the defective sensing electrodes. The test solution has been applied at the system level where an analogue multiplexer, an LCD, and a microcontroller have been used to achieve a real time condition monitoring technique

Test strategies for electrode degradation in bio-fluidic microsystems.

Electrode technology is fundamental to numerous actuation and sensing functions in bio-fluidic microsystems that target portable bio-analytical instruments. Within these systems high levels of reliability and robustness are crucial and normally complemented by requirements for extremely low probabilities of false positives or negatives being generated. New methods of validating functionality and integrity of the reading are hence required. Embedded test and condition monitoring are crucial technologies for delivering these capabilities. This paper presents two solutions for detecting degradation in electrodes that interface to fluidic or biological systems. In the first solution, a low frequency, impedance based method for identifying degraded structures within an array is proposed. This method depends on measuring and comparing the impedance of each sensing electrode. This research is backed up by physical measurements from an electrode array for drug testing on cardiac and neuron tissue. In the second solution, a mid-frequency oscillation test technique is proposed that is sensitive to degradation in the bio-fluidic interface capacitance contamination and fouling