7 ms·
> out of something that normally doesn't move (polycrystalline silicon) More commonly, bulk micromachined MEMS devices are monocrystalline. > and is very frag
by nwiswell 2y ago
> out of something that normally doesn't move (polycrystalline silicon)
More commonly, bulk micromachined MEMS devices are monocrystalline.
> and is very fragile at that
Normalizing for density, monocrystalline silicon is stronger than steel!
- theideaofcoffee 2y agoWhoops, yep, thanks for the correction! What's a Greek prefix between friends (save for crystal properties).
- rcxdude 2y ago>Normalizing for density, monocrystalline silicon is stronger than steel! So's glass, and silicon's a lot like glass (very brittle)
- nwiswell 2y agoGlass has a tensile strength more than an order of magnitude below mono-Si. The elastic modulus for soda-lime is within a factor of 2, but that's not usually what is meant by "strength", rather "stiffness". You're right that fracture toughness is comparable, but that's not usually as relevant in a MEMS context: for one thing there's less potential for unanticipated collisions, but also crack propagation is significantly inhibited at microscopic length scales.