The YouTube video The AMAZING Design of the Parker Solar Probe - Smarter Every Day 198 is quite interesting, as is the video Destin's second "Smarter" channel's video Scientist Interview: Dr. Tony Case (Parker Solar Probe).
At about 03:15 in the second video, Instrument Scientist and Deputy-PI of the Solar Probe (Faraday) Cup, part of the Solar Wind Electrons Alphas and Protons Suite (SWEAP) and astrophysicist Dr. Tony Case describes the details of the construction of Parker's Faraday Cup, which is literally the hottest part of the mission!
The grid is made of tungsten, and the wire bringing the signal back inside the probe to be measured is made of niobium, and uses sapphire beads as insulation.
There is a nearly 90 degree bend in the high voltage feed, and at that point the wire is insulated with a sapphire elbow according to Dr. Case.
How are sapphire elbows made? Is it a cast material (fused sapphire) or is this a hunk of sapphire that's been somehow drilled and machined into a piece of elbow macaroni? Sapphire isn't an easy material to work with!