As for the steepening hook, by laying this metal on a thin layer of standard metal (most of the metals I saw were wires ~.3mm diameter.) It would bend away from the standard metal towards the smart metal, steepening.
How efectively this can be done, I haven't a clue, I'll have to look at the range of motion on these things. But I belive they are already used in robotics. The change in size does increase with increased current but I doupt its a linear thing. Guessing at it needing a greater increase in current for the same shortening once already under current. They do shorten reliably however.
Anyone has has a go at this, good luck.
