PE2-4.4 Micro Sensors

Work through these

• Principles of micro sensors with examples

  What changes when a sensor is made small, which is the theme of the whole topic. Surface forces start to dominate volume forces, and that changes which principles remain usable.

• Force and pressure micro sensors

  The small-scale versions of the force and pressure devices from the previous topic. Comparing them shows what miniaturisation actually bought.

• Position and speed micro sensors

  Measuring position and speed at this scale, which is how mechanical systems are instrumented without adding mass.

• Acceleration micro sensors

  The example worth understanding in full: a tiny proof mass on springs, its deflection read as a capacitance change. It is in every phone and it is the same principle as the seismic transducer above.

• Chemical sensors and biosensors

  Sensing chemistry and biology at small scale, which is where the field meets medicine. The selectivity problem is harder here than the sensing problem.

• Temperature micro sensors

  Temperature at small scale, which is straightforward and widely integrated. It is often on the same die as the sensor it compensates.

• Flow micro sensors

  Measuring flow in channels a hair's width across, which is what microfluidics needs. It closes the topic on the application area growing fastest.