artificial limb SMA cooling

this device can pull a 20 kg bag of cement up with 24v, 2.6 amp. so parts are 3d printed, flat long parts cut with co2 laser.
the 3d printed model was posted a couple of years ago. this is one of front legs.
the work circle is not good for 0.5mm dia muscle wire, thanks to the water in the sponge strip (cut with the laser off a washing pad). contraction is instant but cooling is ...
please see the video:
https://youtu.be/hHddBv2kA48