Microspheres are tiny particles that have many applications, for example in cosmetics$,$ pharmaceuticals, or biomedical imaging. They are usually made of glass, ceramic, or plastic. In this assignment, we consider making microparticles with specific geometries from silicon.

$-$Describe a process to make silicon micro$-$cubes with a side length of about $500$ m$.$

$-$Describe a process to make silicon micro$-$octahedra with a diameter of about $500$ m$.$

$-$ Describe a process to make silicon micro$-$particles that look like our silicon origami model, but with a side length of about $500$ m$.$ This would be a cube whose faces are $\{100\}$ planes, the edges are chamfered to expose $\{110\}$ planes, and the corners are chamfered to expose $\{111\}$ planes. Admittedly, as of this writing, I don't have an obvious answer in mind, so I am looking forward to discovering your creative solutions.$$

For all processes, you can assume that you start with a plain silicon wafer of your choice. If necessary, you can bond this wafer onto a support wafer made of silicon, glass, or another suitable material. List the main processing steps. Some top$-$view or cross$-$section sketches may also be useful.