Why not use a principle similar to that in the wireline industry, oilfield technology?
When a wireline is attached to the Fish Neck of a Top Sub, it is simply threaded into a hole, like threading a needle. A set of pawls located in slots then grab the wire. As the wireline tension increases, the pawls grab the wire harder. Thus you have a situation where resistance to slip is proportional to wireline tension.
I have used this mechanism extensively, most recently to grab a wire specimen for a Universeral Testing Machine. We got a good stress/strain curve on the wire without slippage. Most importantly, the wire broke at a location other than where the pawls had grabbed it.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada