Optimal path evolution in a dynamic distributed MEMS-based conveyor

We consider a surface designed to convey fragile and tiny micro-objects. It is composed of an array of decentralized blocks that contain MEMS valves. We are interested in the dynamics of the optimal path between two blocks in the surface. The criteria used for optimal paths are related to the degradation of the MEMS, namely its remaining useful life and its transfer time. We study and analyze the evolution of the optimal path in dynamic conditions in order to increase the efficiency of the conveying surface. Simulations show that during usage the number of optimal paths increases, and that position of sources greatly influences surface lifetime

Post-prognostics decision making in distributed MEMS-based systems

In this paper, the problem of using prognostics information of Micro-Electro-Mechanical Systems (MEMS) for post-prognostics decision in distributed MEMS-based systems is addressed. A strategy of postprognostics decision is proposed and then implemented in a distributed MEMS-based conveying surface. The surface is designed to convey fragile and tiny microobjects. The purpose is to use the prognostics results of the used MEMS in the form of Remaining Useful Life (RUL) to maintain as long as possible a good performance of the conveying surface. For that, a distributed algorithm for distributed decision making in dynamic conditions is proposed. In addition, a simulator to simulate the decision in the targeted system is developed. Simulation results show the importance of the postprognostics decision to optimize the utilization of the system and improve its performance

Interface Circuits for Microsensor Integrated Systems

ca. 200 words; this text will present the book in all promotional forms (e.g. flyers). Please describe the book in straightforward and consumer-friendly terms. [Recent advances in sensing technologies, especially those for Microsensor Integrated Systems, have led to several new commercial applications. Among these, low voltage and low power circuit architectures have gained growing attention, being suitable for portable long battery life devices. The aim is to improve the performances of actual interface circuits and systems, both in terms of voltage mode and current mode, in order to overcome the potential problems due to technology scaling and different technology integrations. Related problems, especially those concerning parasitics, lead to a severe interface design attention, especially concerning the analog front-end and novel and smart architecture must be explored and tested, both at simulation and prototype level. Moreover, the growing demand for autonomous systems gets even harder the interface design due to the need of energy-aware cost-effective circuit interfaces integrating, where possible, energy harvesting solutions. The objective of this Special Issue is to explore the potential solutions to overcome actual limitations in sensor interface circuits and systems, especially those for low voltage and low power Microsensor Integrated Systems. The present Special Issue aims to present and highlight the advances and the latest novel and emergent results on this topic, showing best practices, implementations and applications. The Guest Editors invite to submit original research contributions dealing with sensor interfacing related to this specific topic. Additionally, application oriented and review papers are encouraged.

Thermal optimization of a polyimide V-groove actuator for a walking micro-robot

The objective of this thesis was to develop a Finite Element Model for the Polyimide V-groove actuator (fabricated by T. Ebefors, Sweden). Extensive FEM simulations for this MEMS actuator were performed using ANSYS 5.6. An optimization module was used to improve the performance of the existing design. A substantial improvement in the performance was observed for the proposed design. In short, this research established a methodology that can be extended for modeling and simulation of other MEMS devices. A computer simulated FEM model for heat and deflection analysis was validated for two configurations of the Polyimide V-groove Actuator (i.e. a Serpentine Heater Configuration and a Polysilicon Heater Configuration). Some differences between the simulated and experimental results (reported by T. Ebefors) were noted in the low frequency domain. The role of various parameters including thermal conductivity and wall temperature has been investigated to eliminate these discrepancies. To improve the performance of the actuator, different design geometries were proposed and each design was simulated for various frequencies. Significant performance improvement was observed for the case of uniform diaphragm thickness at the V-groove bottom . The optimization module of ANSYS was used for optimizing the thickness of the silicon diaphragm (referred to as single variable optimal design ). Steady state analysis showed that there is an improvement in the deflection and the force developed for the single variable optimal design over T. Ebefors\u27 design. Transient analysis showed improvement in the cooling characteristics of the single variable optimal design over T. Ebefors\u27 design. In the second optimization exercise (referred to as overall optimization ), all the dimensions of the V-grooves were used as design variables. A three times increase in the deflection was observed in the overall optimal design as compared to the single variable optimal design. Also, there is a three times reduction in the maximum force developed by the overall optimal design. Transient analysis revealed that the overall optimal design has better cooling characteristics compared to the single variable optimal design. Hence, for an application where the applied force is not a critical factor, the overall optimal design would be suitable, e.g. if a lightweight mirror is mounted on the end of the actuator, the mirror can be moved through a larger distance. For micro robotics applications, the optimal design with a single variable could be useful, where the load carrying capacity of this design is superior

A Real-Time Positioning System of Manufacturing Carriers Deploying Wireless MEMS Accelerometers and Gyroscopes

Modern manufacturing systems face ever-increasing pressure to maximize efficiency of production processes, minimize downtime due to unexpected deviations from normal operation, and maintain agility in dynamic market conditions. Detailed, real-time asset tracking is essential for achieving these goals. Pallets are widely-used for transporting raw materials, intermediate products, and final products in automated assembly and manufacturing lines. A sophisticated pallet monitoring system can provide possibilities for optimizing pallet routing in real time, enable dynamic scheduling changes, and historical traceability required for error diagnosis and repair. Traditionally, pallets are monitored by networks of sensors, such as RFID readers or proximity sensors to collect location data. These sensor networks are rarely dense enough to provide precise continuous data about pallet location. Real-time pallet tracking data is thus limited to recording timestamps at static checkpoints. This thesis presents an asset-aware management tool for continuous pallet location monitoring based on event logs obtained from intelligent wireless devices embedded in each pallet. Each wireless device, equipped with a 3-axis accelerometer and a 3-axis gyroscope, provides accurate information about pallet movement. The raw sensor data is pre-processed into an event stream, which is sent to a server over a 6LoWPAN network. The software developed in this research implements an algorithm for processing event logs to determine exact pallet location using artificial intelligence techniques. Calculated pallet position can be provided to high-level enterprise systems, and to manufacturing execution systems for use in scheduling, routing, and visualization of the production line. Designing the SCADA system was also part of this thesis. The solution was successfully deployed in the FASTory, a 12-cell light assembly line in the Factory Automation Systems and Technologies Laboratory (FAST-lab.) at Tampere University of Technology, as part of eSONIA, a European Commission-cofunded research project on using service-enabled embedded devices for realizing an asset-aware, self-recovering plant. The proposed solution demonstrates a novel approach for continuous, real-time pallet location tracking based on wireless sensors

Advanced Control of the Permanent Magnet Synchronous Motor

The electrical machines are the core of the electrical drives. By introducing the vector control techniques for the alternative current machines, the high performances in drive systems are attained. One on the alternative current machines is the permanent magnet synchronous motor (PMSM). Due to their advantages, it becomes a very popular solution in the electrical drive field. In this chapter, an optimal control solution applied on the PMSM based on the Riccati solution is developed by the author. The objectives of the optimal control drive system are regulation, stability, robustness to the load disturbance variation and the energy reduction. Comparative with the conventional cascaded control, the proposed solution conducts up to 10% to energy efficiency improvement in transient regimes. The efficiency improvement depends on the chosen weighted matrices. Both the conventional and optimal controllers are implemented in Matlab-Simulink. The real-time solution based on the dSpace platform is provided

DESIGN OF SMART SENSORS FOR DETECTION OF PHYSICAL QUANTITIES

Microsystems and integrated smart sensors represent a flourishing business thanks to the manifold benefits of these devices with respect to their respective macroscopic counterparts. Miniaturization to micrometric scale is a turning point to obtain high sensitive and reliable devices with enhanced spatial and temporal resolution. Power consumption compatible with battery operated systems, and reduced cost per device are also pivotal for their success. All these characteristics make investigation on this filed very active nowadays. This thesis work is focused on two main themes: (i) design and development of a single chip smart flow-meter; (ii) design and development of readout interfaces for capacitive micro-electro-mechanical-systems (MEMS) based on capacitance to pulse width modulation conversion. High sensitivity integrated smart sensors for detecting very small flow rates of both gases and liquids aiming to fulfil emerging demands for this kind of devices in the industrial to environmental and medical applications. On the other hand, the prototyping of such sensor is a multidisciplinary activity involving the study of thermal and fluid dynamic phenomenon that have to be considered to obtain a correct design. Design, assisted by finite elements CAD tools, and fabrication of the sensing structures using features of a standard CMOS process is discussed in the first chapter. The packaging of fluidic sensors issue is also illustrated as it has a great importance on the overall sensor performances. The package is charged to allow optimal interaction between fluids and the sensors and protecting the latter from the external environment. As miniaturized structures allows a great spatial resolution, it is extremely challenging to fabricate low cost packages for multiple flow rate measurements on the same chip. As a final point, a compact anemometer prototype, usable for wireless sensor network nodes, is described. The design of the full custom circuitry for signal extraction and conditioning is coped in the second chapter, where insights into the design methods are given for analog basic building blocks such as amplifiers, transconductors, filters, multipliers, current drivers. A big effort has been put to find reusable design guidelines and trade-offs applicable to different design cases. This kind of rational design enabled the implementation of complex and flexible functionalities making the interface circuits able to interact both with on chip sensors and external sensors. In the third chapter, the chip floor-plan designed in the STMicroelectronics BCD6s process of the entire smart flow sensor formed by the sensing structures and the readout electronics is presented. Some preliminary tests are also covered here. Finally design and implementation of very low power interfaces for typical MEMS capacitive sensors (accelerometers, gyroscopes, pressure sensors, angular displacement and chemical species sensors) is discussed. Very original circuital topologies, based on chopper modulation technique, will be illustrated. A prototype, designed within a joint research activity is presented. Measured performances spurred the investigation of new techniques to enhance precision and accuracy capabilities of the interface. A brief introduction to the design of active pixel sensors interface for hybrid CMOS imagers is sketched in the appendix as a preliminary study done during an internship in the CNM-IMB institute of Barcelona

OCM 2021 - Optical Characterization of Materials

The state of the art in the optical characterization of materials is advancing rapidly. New insights have been gained into the theoretical foundations of this research and exciting developments have been made in practice, driven by new applications and innovative sensor technologies that are constantly evolving. The great success of past conferences proves the necessity of a platform for presentation, discussion and evaluation of the latest research results in this interdisciplinary field