So what do you do when @jeriellsworth's @tiltfive sends you a sample of the retroreflectors they use to make their table top AR system? Of course I stick it in a Focused Ion Beam Microscope to figure out how they are made by slicing them in half with a beam of metal. [Thread] So more about those spheres. You may be familiar with corner based retroreflectors, where light that enters it bounces off of the 3 surfaces in such a way it comes back directly at the source of the the light. Turns out the glass spheres also work as retroreflectors. (Wikipedia)

The SiTime 1532 is a MEMS osilator used inside of modern Apple devices and is responsible for the iPhones getting getting bricked by Helium thing. I decapped a few of them and imaged them under my SEM. You can see the "tunning forks" responsible for generating the 33kHz clock. Decaping the device cleanly is difficult, what makes it special is how small it is. Instead of being packaged in epoxy like most devices it's entirely encased in silicon, making it challenging to cleanly open up. Regardless it produces some great SEM images.