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This study guide consists of 4 parts, each corresponding to 2 days of study load. Each part contains several sections on different topics that you need to study. Each part also contains assignments for you to practice. Each of the four parts ends with a more challenging assignment: please try these and send us your solutions to get feedback.
This part of the course provides an introduction to Micro-Electro-Mechanical-Systems (MEMS). It explains the basic operating principles of devices like force sensors, pressure sensors, accelerometers and gyroscopes. MEMS devices typically have moving parts on a chip, which are suspended by flexures, i.e. thin strips or membranes that can deform and act like springs. Therefore, an introduction is given into static mechanics and it is shown how to calculate the bending of a beam under a load. A common and easy way to detect a movement or deformation is the use of (piezo-)resistive strain gauges. Here we enter the field of transducer science. Strain gauges belong to the class of modulator type transducers: their electrical resistance depends on the amount of deformation. In modulator type transducers there is no energy flow from one physical domain to the other. Instead, we can describe these transducers by a blank energy flow in the information receiving domain which is modulated by the information in the other domain.
In the second part of the course we will start with another type of transducers: generator type transducers. In generator type transducers the transduction is related to a flow of energy through the transducer and energy can also be stored in the transducer. These transducers can be described in a general way, independent of the domains that are involved. We will see that once we know the so-called energy function, i.e. the energy stored in the transducer as a function of the variables in the physical domains, we know virtually everything about the transducer.
In the third part of the course we continue our analysis of electrostatic transducers. We apply the previously learned material to a practical case: a power sensor that can measure the signal power on a high-frequency transmission line by detecting the electrostatic force. Besides the quasi-static analysis of part 2 we now also consider dynamic behaviour and we calculate the electrical impedance and the transfer function of the device as a function of frequency.
In the last part of the course we have a look at magnetic transducers like a relay, voice coil or loudspeaker. Magnetic transducers also belong to the class of generator type transducers, i.e. the energy function is the key to understand their behaviour.