Jiri Marek

MEMS for automotive and consumer electronics

A car is skidding, and stabilizes itself without driver intervention; a laptop falls to the floor, and protects the hard drive by parking the read/write drive head automatically before impact; an airbag fires before the driver/occupant involved in an impending automotive crash impacts the steering wheel, thereby significantly reducing physical injury: - all systems involved are based exclusively on MEMS sensors. These crucial MEMS-sensor components of electronic control systems are making system reaction to human needs more intelligent, precise, and at much faster rates than humanly possible.

Acceleration sensor and measurement method

An acceleration sensor has a seismic mass having movable electrodes. The movable electrodes are designed as differential capacitors between two fixed electrodes. Also provided are additional electrodes which are arranged opposite movable electrodes or opposite bending elements on which the seismic mass is suspended. Electrical voltages which are evaluated by the evaluation circuit as acceleration can be applied to the additional electrodes.

Micromachined thermoelectrically driven cantilever structures for fluid jet deflection

The design, fabrication, and performance of bimorph cantilever structures for direction control of laminar jet flow are reported. The fabrication process comprises standard IC technologies and additional silicon micromachining techniques. The design parameters for the structures are obtained using analytical approximations and numerical simulations. Forced convection as the decisive cooling mechanism proves to be very effective, resulting in an excellent dynamic response of the thermoelectrically activated structures. Experimental testing confirmed the predicted stationary and transient behavior of 1-mm-long and 1-mm-wide actuators, which are able to control hydraulic power at pressure levels of up to 4 bar, flow rates of up to 150 ml/min, and time constants of about 1 ms.<<ETX>>

MEMS (Micro-Electro-Mechanical Systems) for Automotive and Consumer Electronics

MEMS sensors gained over the last two decades an impressive width of applications: (a) ESP: A car is skidding and stabilizes itself without driver intervention (b) Free-fall detection: A laptop falls to the floor and protects the hard drive by parking the read/write drive head automatically before impact. (c) Airbag: An airbag fires before the driver/occupant involved in an impending automotive crash impacts the steering wheel, thereby significantly reducing physical injury risk. MEMS sensors are sensing the environmental conditions and are giving input to electronic control systems. These crucial MEMS sensors are making system reactions to human needs more intelligent, precise, and at much faster reaction rates than humanly possible. Important prerequisites for the success of sensors are their size, functionality, power consumption, and costs. This technical progress in sensor development is realized by micro-machining. The development of these processes was the breakthrough to industrial mass-production for micro-electro-mechanical systems (MEMS). Besides leading-edge micromechanical processes, innovative and robust ASIC designs, thorough simulations of the electrical and mechanical behaviour, a deep understanding of the interactions (mainly over temperature and lifetime) of the package and the mechanical structures are needed. This was achieved over the last 20 years by intense and successful development activities combined with the experience of volume production of billions of sensors. This chapter gives an overview of current MEMS technology, its applications and the market share. The MEMS processes are described, and the challenges of MEMS, compared to standard IC fabrication, are discussed. The evolution of MEMS requirements is presented, and a short survey of MEMS applications is shown. Concepts of newest inertial sensors for ESP-systems are given with an emphasis on the design concepts of the sensing element and the evaluation circuit for achieving excellent noise performance. The chapter concludes with an outlook on arising new MEMS applications such as energy harvester and micro fuel cells.

Automotive MEMS sensors — Trends and applications

A car is skidding and stabilizes itself without driver intervention; an airbag fires before the driver involved in an impending automotive crash impacts the steering wheel thereby significantly reducing physical injury risk; — all these systems are based exclusively on MEMS sensors. These crucial MEMS sensor components of electronic control systems are making system reactions to human needs more intelligent, precise, and at much faster reaction rates than humanly possible.

MEMS—Micro-Electromechanical Sensors for the Internet of Everything

Automotive safety applications were the cradle of the MEMS market over many years. Their persistent improvement in cost and size launched the wide application of MEMS in consumer applications as well, starting from year 2009, outpassing in numbers the automotive MEMS volume within only 3 years. The consumer MEMS annual growth rate today is 18 %. Following a steep learning-curve, their form factor was reduced by more than 10-times within 5 years. Concurrently, cost, embodied materials and energy consumption of MEMS devices came down to an extent that basic integrated units contain now a multitude of sensors, with 9 degrees-of-freedom, by 2013. Virtually unlimited new applications which are strong in sensors emerge, enabling the Internet-of-Everything.

Mikromechanische Sensoren für Automobilanwendungen

Mikromechanische Sensoren sind zu einem unverzichtbaren Element der Automobilelektronik geworden. In diesem Beitrag der Robert Bosch GmbH werden Anwendungen fur mikromechanische Sensoren im Automobil vorgestellt, und es wird einen Ausblick auf zukunftige Einsatzgebiete gegeben.

Material-related effects on wet chemical micromachining of smart MEMS devices

Smart MEMS devices such as pressure, mass flow and yaw rate sensors are presented in detail. One common point of this range of devices is their fabrication technology regarding anisotropic etching. This paper is first meant to give a short review upon the applications processed by using wet chemical etching in KOH-solutions. Furthermore, we will discuss about the impact of material and process related defects in the silicon crystal and on the anisotropic etching behavior.