Glass fiber doesn't have to be brittle at all - in fact, in the middle of the 20th century, it was made into a silk-like fabric; the Levitt house where I grew up originally came with sheer Fiberglas™ curtains on its picture window. (The practice of making textiles out of it diminished when the health risks of microscopic fragments of glass fiber became known.) But almost all of the polymer fibers developed in the 20th century contain nothing but carbon, oxygen, hydrogen, and nitrogen - scarcely even a sulfur atom here and there, never mind any other elements. Surely the AIs could manufacture these easily enough.

I already have enough bottle openers (the old "church key" style) for my limited needs, and what they look like is unimportant. I'd love to be able to equip my cabinets with some of the more extraterrestrial-looking pulls and knobs, though!