MEMS Accelerometers

Micro-electro-mechanical system (MEMS) devices are widely used for inertia, pressure, and ultrasound sensing applications. Research on integrated MEMS technology has undergone extensive development driven by the requirements of a compact footprint, low cost, and increased functionality. Accelerometers are among the most widely used sensors implemented in MEMS technology. MEMS accelerometers are showing a growing presence in almost all industries ranging from automotive to medical. A traditional MEMS accelerometer employs a proof mass suspended to springs, which displaces in response to an external acceleration. A single proof mass can be used for one- or multi-axis sensing. A variety of transduction mechanisms have been used to detect the displacement. They include capacitive, piezoelectric, thermal, tunneling, and optical mechanisms. Capacitive accelerometers are widely used due to their DC measurement interface, thermal stability, reliability, and low cost. However, they are sensitive to electromagnetic field interferences and have poor performance for high-end applications (e.g., precise attitude control for the satellite). Over the past three decades, steady progress has been made in the area of optical accelerometers for high-performance and high-sensitivity applications but several challenges are still to be tackled by researchers and engineers to fully realize opto-mechanical accelerometers, such as chip-scale integration, scaling, low bandwidth, etc

Hybrid Micro-Electro-Mechanical Tunable Filter

While advantages such as good thermal stability and processing-chemical compatibilities exist for common monolithic-integrated micro-electro-mechanically tunable filters (MEM-TF) and MEM-tunable vertical cavity surface emitting lasers (MT-VCSEL), they often require full processing to determine device characteristics. Alternatively, the MEM actuators and the optical parts may be fabricated separately, then subsequently bonded. This hybrid approach potentially increases design flexibility. Since hybrid techniques allow integration of heterogeneous material systems, best of breed compound optoelectronic devices may be customized to enable materials groups to be optimized for tasks they are best suited. Thus, as a first step toward a hybrid (AlxGa1-xAs-polySi) MT-VCSEL, this dissertation reports the design, fabrication, and demonstration of an electrostatically actuated hybrid MEM-TF. A 250x250-µm2, 4.92-µm-thick, Al0.4Ga0.6As-GaAs distributed Bragg reflector was successfully flip-bonded to a polySi piston electrostatic actuator using SU-8 photoresist as bonding adhesive. The device demonstrated 53nm (936.5 - 989.5nm) of resonant wavelength tuning over the actuation voltage range of 0 to 10 V

Sensors for Robotic Hands: A Survey of State of the Art

Recent decades have seen significant progress in the field of artificial hands. Most of the surveys, which try to capture the latest developments in this field, focused on actuation and control systems of these devices. In this paper, our goal is to provide a comprehensive survey of the sensors for artificial hands. In order to present the evolution of the field, we cover five year periods starting at the turn of the millennium. At each period, we present the robot hands with a focus on their sensor systems dividing them into categories, such as prosthetics, research devices, and industrial end-effectors.We also cover the sensors developed for robot hand usage in each era. Finally, the period between 2010 and 2015 introduces the reader to the state of the art and also hints to the future directions in the sensor development for artificial hands

Optical Fiber Interferometric Sensors

The contributions presented in this book series portray the advances of the research in the field of interferometric photonic technology and its novel applications. The wide scope explored by the range of different contributions intends to provide a synopsis of the current research trends and the state of the art in this field, covering recent technological improvements, new production methodologies and emerging applications, for researchers coming from different fields of science and industry. The manuscripts published in the Special issue, and re-printed in this book series, report on topics that range from interferometric sensors for thickness and dynamic displacement measurement, up to pulse wave and spirometry applications

Medical semiconductor sensors: a market perspective on state-of-the-art solutions and trends

The aim of this Master Thesis is to analyse the worldwide state-of-the art market solutions and trends in semiconductor sensors within medical applications; specially magnetic and pressure sensors, with the intention of developing a potential entry plan of Infineon Technologies AG into this market. For that purpose, a fit between a top-down and bottom-up qualitative and quantitative estimation of the medical semiconductor sensor’s market size has been made; with application units, sensor volumes and sensor revenues, with a horizontal scope of five years. Once understood the existing market, some insight into the competitive landscape is provided, where the key suppliers are analysed in terms of product portfolio and revenue share estimates, on an application basis. And also, a spotlight on innovation and trends at three levels – healthcare, medical devices and medical semiconductor sensors – is presented, to forecast a possible evolution of the fore-mentioned market. The research that has been conducted is based on three main sources of information; internal contacts (i.e. within Infineon), external contacts (most of them through internal references) and internet research. Access to market research company’s reports and interviews has been particularly helpful, to complement extensive internet research. Outcomes of this study indicate that the global medical semiconductor magnetic sensor market reveals low revenue potential; as most of the applications are yet innovation fields. Reed switch replacement in battery-powered medical devices can be an opportunity for magnetic switches. However, this project suggests that there is a key investment opportunity: magnetic beads for viral detection with spintronics sensors. The global medical semiconductor pressure sensor market seems a fairly mature market; the gross part of the revenue comes from blood pressure measurement. Blood pressure measurement might be an opportunity for existing automotive semiconductor pressure sensor products. Furthermore, this report suggests that the future of blood pressure measurement might tend towards implantable pressure sensors, with a non-significantly different technological basis. To conclude, this report unveils certain business opportunities for Infineon’s semiconductor magnetic and pressure sensor products; and puts special focus on the development of derivative products to pioneer the commercialization of innovative medical applications, with a forecasted huge revenue potential

Methods and Sensors for Slip Detection in Robotics: A Survey

The perception of slip is one of the distinctive abilities of human tactile sensing. The sense of touch allows recognizing a wide set of properties of a grasped object, such as shape, weight and dimension. Based on such properties, the applied force can be accordingly regulated avoiding slip of the grasped object. Despite the great importance of tactile sensing for humans, mechatronic hands (robotic manipulators, prosthetic hands etc.) are rarely endowed with tactile feedback. The necessity to grasp objects relying on robust slip prevention algorithms is not yet corresponded in existing artificial manipulators, which are relegated to structured environments then. Numerous approaches regarding the problem of slip detection and correction have been developed especially in the last decade, resorting to a number of sensor typologies. However, no impact on the industrial market has been achieved. This paper reviews the sensors and methods so far proposed for slip prevention in artificial tactile perception, starting from more classical techniques until the latest solutions tested on robotic systems. The strengths and weaknesses of each described technique are discussed, also in relation to the sensing technologies employed. The result is a summary exploring the whole state of art and providing a perspective towards the future research directions in the sector

NASA Tech Briefs, September 2001

Topics include: special coverage section on sensors, and sections on electronic components systems, software, materials, machinery/automation, manufacturing/fabrication, bio-medical, book and reports, and a special section of Photonics Tech Briefs