Like, yes, i know it’s electric and such. But I recently talked to an engineer and he, as I understand, said that there are still switches and other mechanics but microscopic inside CPUs and circuit boards.
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Not in CPUs, but there are moving devices on silicon chips – they are called MEMS (micro electro-mechanical systems). If your phone knows which way up it is then that is because of a MEMS gravity sensor. Your phone also probably has a MEMS accelerometer.
These MEMS devices typically make use of long thin (at the scale of microchips) arms [like so](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRDgbbUndAncTqGr_yTKZ4JKU352_HriiZaew&usqp=CAU) which are attached at one end and free to wiggle at the other. As the end of the arm gets near one side or the other you can detect that proximity electrically and so work out how the arm is wiggling. This tells you how the whole device is moving etc. The exact techniques used to make these structures are not particularly complex, but really quite hard to explain without diagrams. Suffice to say that chips are built up in layers, but you can also etch material away so you can build up one of these long arms and then etch away the material underneath that was holding it to the body of the chip (by making the material in that particular layer susceptible to etching). Interestingly we actually have micromachining tools (sort of like miniature drills) that can work down to the sizes of chips. So you might build up a few layers, drill out some holes, build up some more layers, do some etching etc.
A really cool emerging technology is microfluidics where you have tiny pipes and channels in your chip that small amounts of fluid can flow through and be tested.
[A cool MEMS device](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcR2ohvxLMk7XfsAKG0_BNEfGWmWOUEPx4SOgw&usqp=CAU)
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