In an article with the catchy title Necrobotics: Biotic Materials as Ready-to-Use Actuators published by Advanced Science, the boffins said that evolution has perfected many designs that could be useful in robots, and that spiders have proven especially interesting.
Spiders' legs "do not have antagonistic muscle pairs; instead, they have only flexor muscles that contract their legs inwards, and hemolymph (i.e., blood) pressure generated in the prosoma (the part of the body connected to the legs) extends their legs outwards.
The authors thought if they could generate and control a force equivalent to blood pressure, they could make a dead spider's legs move in and out, allowing them to grip objects and release them again.
Unfortunately that meant killing a wolf spider by exposing it to cold for a week and then injecting the spider's prosoma with glue. By leaving the syringe in place and pumping in or withdrawing glue, the researchers were able to make the spider's legs contract and grip.
he article claims that's a vastly easier way to make a gripper than with conventional robotic techniques that require all sorts of tedious fabrication and design efforts. It also was a change from pulling the wings off flies. Of course boffins know the dangers of experimenting on flies.
"The necrobotic gripper is capable of grasping objects with irregular geometries and up to 130 percent of its own mass," the article notes.
Given the spider had done nothing, we would have thought that reanimating it in any form would be the stuff of a b grade revenge horror movie.