Although the lifespan of this type of robot is short, this work is not without an environmental benefit, which is that spiders are biodegradable, so using them as robot parts will reduce the amount of waste generated by the robots.
At a time of growing concern about robots due to a robot that recently broke the finger of a 7-year-old child during a chess match in Moscow, researchers from the American “Rice University” presented new research that a robot show whose design is mainly based on a dead spider.
According to the study, published in the journal “Advanced Science” on July 25, the dead spider robot moves and grabs things like a “zombie” straight out of a science fiction movie.
Turning dead spiders into robots might sound like a scary scenario idea, but in reality, the trend could have tangible benefits. For example, spiders’ legs can grip large, delicate and irregular objects firmly and gently without breaking them.
The Science of “Necroboty”
The story began when Fei Yap, a graduate student in mechanical engineering at Rice University, saw a dead spider in the hallway and wondered if it could be used as a robotic element. So, I teamed up with mechanical engineer Daniel Preston, and they figured out a way to make a dead wolf spider’s legs stick to things. They called this new type of robotics “Necrobotics”.
Lupus spiders have a large body and thin legs, and they catch the prey with the front legs and then smash their prey with two hair-covered front canines. Strangely enough, its legs do not have muscles to stretch, but instead move its legs by hydraulic pressure, because the spider has a so-called “cephalothorax” and consists of the head and chest fused together, and it contracts and steers internal body fluids to the bones, causing them to stretch.
So, the team inserted a needle into the vertical thorax chamber and covered the tip of the needle with a coil of glue. The pressure with a small pump of air through the syringe was enough to activate the spider’s legs and the full extent of movement to be achieved in less than one second.
“We took the spider and put the needle in it without knowing what would happen,” says Yap in a video. “We had an estimate of where we wanted to put the needle. And when we did, we got it right the first time,” she says.
The team was able to get the dead spider to grip a small ball and used this experiment to determine peak grip strength. Next, the team members used a dead spider to pick up the small objects. They also showed that the spider can carry the weight of another spider of approximately the same size.
Necrobotics applications and disadvantages
Preston’s lab specializes in soft robotic systems that often use unconventional materials, as opposed to hard plastics, metals and electronics. “These soft robots are so much fun because we’re using previously unexplored types of machining and materials,” Preston said.
While most components of human-made robots are very complex, so are spiders, but they are abundant. “The concept of necrobotics proposed in this work makes use of unique designs found in nature that may be complex or even impossible to replicate artificially,” the researchers say in their paper.
“One of the applications where we could see this work being used is micromanipulation, and that could include things like microelectronic devices,” says Preston.
But one of the disadvantages of a dead spider’s clutch is that it starts to wear after two days or after a thousand open and close cycles. The researchers experimented with coating tarantulas with beeswax and found that their mass drop was 17 times less than that of an uncovered spider over 10 days, meaning it retains more water and its hydraulic system can work longer.
“We think it’s related to problems with dry joints,” explains Preston. “And we think we can overcome this by applying polymeric coatings.”
Although the use of these types of robots is short, this work is not without an environmental benefit, which is that spiders are biodegradable, so using them as robot parts will reduce the amount of waste generated by the robots.
“Although it appears to have come back to life, we’re pretty sure it’s not alive, and in this case we’re using it strictly as a substance derived from a once-living spider… It gives us something really useful,” Preston said.