When Fei Yap, a mechanical engineering graduate student, saw a dead spider curled up in a hallway, she wondered if it could be used as a robotic element.
Turning dead spiders into mechanical pens may seem like some kind of horrifying scenario, but it can have tangible benefits. And the spider’s legs can firmly and gently grip large, fragile and irregular objects without breaking them.
So, in collaboration with mechanical engineer Daniel Preston, Yap and her colleagues at Rice University have found a way to make a dead wolf spider’s legs open and cling to objects.
They called this new type of robot “necrobot”.
Ironically, the legs of spiders do not have muscles to stretch, but instead move their legs using hydraulic pressure – they have a so-called prosoma chamber, or head of the chest, which contracts, sending internal body fluids into the legs, causing them to stretch.
So the team inserted a needle into the spider’s head chamber and sealed the tip of the needle with a bead of superglue. Squeezing a small amount of air through the syringe was enough to activate the spider’s legs, reaching full range of motion in less than one second.
“We took a spider, put a needle in it, not knowing what was going to happen,” Yap says in a video on the Rice University website.
The team was able to get a dead spider to grab a small ball, and they used this experiment to determine a peak gripping force of 0.35 millinewtons.
They then demonstrated the use of a dead spider to pick up tiny items and electronics, including having a clutch unplug a wire attached to an electrical panel and then move a block of polyurethane foam.
They also showed that the spider could support the weight of another spider of about the same size.
And because the spiders stretch their legs, applying hydraulic pressure to the thoracic portion of their head when they die, the hydraulic system no longer works. The spider’s leg flexors tighten, but since the muscles only work in one direction, the spider curls up.
While most of the components of human-made robots are very difficult to manufacture, spiders are indeed.
“One of the applications where we can see this is in microprocessing, and this can include things like microelectronic devices,” Preston says in the video.
This study was published in the journal cutting edge science.
Source: Science Alert.