Review and Summary

[From the last episode: Meglab uses IoTThe Internet of Things. A broad term covering many different applications where "things"  are interconnected through the internet. technology in mines to keep miners safer, keep track of equipment, and manage ventilation.]

OK, we’ve covered a lot of ground since May. Let’s take a big breath and review!

• We took a quick detour to look at an Alexa bug that ended up sending a conversation snippet to someone in a contacts list. Oops!
• We then looked at sensorsA device that can measure something about its environment. Examples are movement, light, color, moisture, pressure, and many more. and actuatorsA way of controlling some device electronically. It might turn the device on or off or change a setting or property or do any other thing that the device is capable of. generically:
  • We introduced the subject and the challenges that they pose.
  • We then looked at the notion of building mechanical devices on a silicon wafer.
  • We then worked through the three essential elements for building things on siliconAn element (number 14 in the periodic table) that can be a semiconductor, making it the material of preference for circuits and micro-mechanical devices.:
    • Adding materials
    • Removing materials
    • Being selective about where materials end up
  • We looked at the kinds of dimensions involved in these tiny devices
  • We introduced MEMS technology – critical for building mechanical devices on silicon wafersIn the context of making circuits, sensors, and actuators, a thin, round slice of pure silicon. Multiple devices will be made on it; it will then be sliced up to separate the individual chips..
  • We used a swimming-pool analogy to demonstrate how MEMS works, and how it’s really different from what you might expect.
    • We first explored how you would probably dig the pool out in the real, macro world
    • We then compared that to what you would do using a MEMS-like approach. It’s not obvious, and it takes a lot more steps.
  • We looked at some of the options available when using MEMS technology.
  • Finally, we reviewed the general structure of a sensor. Yeah, so many things to think about before we even talk about our first real sensor.
• We then launched into an actual sensor – probably the most common MEMS sensor out there: the accelerometer, which measures how much acceleration it feels (if any – which is a trick comment, since, if you read carefully, you know that, at least here on earth, there’s always acceleration). In order to explore this one more thoroughly and to help with the next sensors we’ll look at, we had to introduce a few new notions.
  • We looked at “degrees of freedom,” what you might think of as “dimensions.”
  • We explored how you might measure acceleration in three different dimensions at the same time.
  • And finally, we looked at how you can turn the mechanical indicators of acceleration into electrical signals that we can then deliver to the rest of the electronics so that they can do something with the acceleration information (like trigger an airbag).
• Finally, we took a break from all the mind-spinning technology to look at another example of a company using IoT technology – this time in the mining industry.

From here, we’re going to keep exploring some of the basic sensors to show you the range of things being done using MEMS and other technologies. More and more of these sensors are being embedded into all kinds of systemsThis is a very generic term for any collection of components that, all together, can do something. Systems can be built from subsystems. Examples are your cell phone; your computer; the radio in your car; anything that seems like a "whole.". Mostly they’re intended to be helpful, although some might be considered surveillance… More on that later.