I previously wrote about a successful synthetic clarinet reed, based on a anisotropic polymer. They aren't the only one, Fiberreed is another, based on what they call a "Hollow Fiber Foamresin Compound", a composite of hollow fibers encased in foam to provide an appropriate balance of lateral and longitudinal stiffness. Sounds plausible. Some of their models incorporate carbon fiber, which interests me, since carbon fiber is one of the strongest and stiffest materials, and dominates a lot of applications. In addition to the usual benefits of artificial materials (no water absorption, longevity) Fiberreed promises reproducibility, and will custom adjust a new reed to match your favorite reed of any type, and then sell you a new copy anytime you want. Like Legere, Fiberreed is single reed only, which I'd guess reflects partly manufacturing simplicity, and partly market size -- there's a lot of sax players out there. Fibracell is another maker, again with a fiber composite, this one with Kevlar and resin, and there are likely more besides.
Bocals are also heavily affected by material, with makers offering a wide range of metal mixes and thicknesses, in addition to lengths and bore variations. (Heckel lists ~6000 stock combinations, even before you start asking about something custom.) Unfortunately, even the best makers seem to suffer wide variability among nominally identical bocals, so the usual advice is to try many, and try them blind as to maker and model. Other materials used include wood, from Paraschos, which seems to make everything out of wood (even clarinet ligatures!). As for carbon fiber, you can buy carbon fiber sax necks from Zen Composites, and Leonardo Fuks has made at least one carbon fiber prototype bocal, shown here. Hard to tell much about how well it works from that short clip, though.