Ohh, I've had my eye on something like this for a long time. The party I'm running is just now hitting sixth circle and I still think most of my ideas are too fatal for them...but you can decide for yourself!
To properly get that mental anguish you need to have a good lead up and a foreboding sense of dread when a trap gets triggered. None of this 'you fall in a pit' or 'rock falls, everyone dies' business. A few ideas off the top of my head include:
1) The classic treasure in a cranny scenario. You have a small hole in a wall, preferably down low or at some other awkward angle. Within it is pitch black, but a high enough perception or clever use of light sources can see that there is definitely treasure in there. Maybe even a simulacrum of the Scavian crown...something really good as far as loot goes to bait the trap. Once a player reaches their arm into it, a clamp drops down around the far side of the hole locking them in place. If he or anyone else attempts to extricate his arm have significant damage dealt and the arm is only partially removed as the clamps squeeze tighter and tighter the more the poor sod struggles. At this point you want to start causing pain and freaking everyone out. Perhaps a small scythe drops down on the other side of the hole, slowly cutting deeper and deeper into the poor suspect's arm, doing low step damage but slowly ramping up. Or perhaps you can just flood the small chamber with pitch and ignite it, burning the poor man's hand horribly until he can get it out. Potential problems with his trap would be a party with a windling. If they actually crawl through the hole this trap goes from being a maimer to a full on murder as the windling is clamped about the torso...but the ensuing terror is good for a laugh for a suitably nasty GM. Another issue with this trap is that there seem to be very few ways to escape it...perhaps the mechanisms on the far side of the wall are delicate enough that a strong enough blow could loosen them, or the hole is large enough that a dextrous enough person with the right equipment could finagle a release catch while he is uncomfortably close to the trapped and screaming individual.
2) Flooding and gas is a great way to ramp up fear and delay death. Both giving the Artificer the emotion he wants, as well as giving the players time to find an escape. I envision a very tall room that starts flooding with water while all the PCs remain within. As the room floods they need to swim to rise with the level of the water, the obsidimen and heavily armored members of the party find themselves in trouble immediately. Also, just to be devilish, you could include a release mechanism for this trap near the top of the chamber...inside a small hole...just about the size of a standard metahuman arm...whether it triggers the trap as above (likely resulting in horror and a total tpk) or is merely there to terrify the party into BELIEVING its a trap is up to the fiendish-ness of the GM. Alternately, instead of having a release catch, have there be a normal Namegiver sized hole at the top of the chamber, if players flee out to the next chamber, they will have to live with the pain and guilt of leaving party member's to drown in the below pit.
3) This last one is sort of a sacrifice scenario. Entering a chamber, it begins to collapse on itself, the ceiling coming down, all entries and exits closing, heck maybe even spikes and buzzsaws and other terrors begin to fill the room. As the party panics and looks about they can find a single release lever. Pulling it will allow for the far door to open and all the traps to cease their advance, however when the lever is released, the door seals shut and all the traps continue their deadly advance. The party needs to either come up with a way to keep the lever pulled (which should be made suitably difficult, maybe it is very sharp, causing pain to the puller and making it impossible to tie a standard rope around, maybe the room is oddly shaped making it impossible to see the lever from the door to avoid most spells, perhaps the traps themselves dispel magic or cut ropes in the room) or they need to decide which party member must stay behind and hold the lever while the rest leave him to his fate. Depending on the party, if someone is left behind holding the lever and the rest leave him, the GM could have the traps all cease and recede right before the last man's inevitable crushing demise. Now the entire party needs to cope with the fact that either they were left to die or they did the leaving...a difficult social issue that a heavy RP party might enjoy tangling with.
I hope these ideas help! If you need anything more specific and/or more cruel (not sure if I can do less) let me know.