If you think dead spider robots are straight out of a horror movie (or your worst nightmares), I’ve got news for you.
Rice University mechanical engineers have turned spider cadavers into what they call “necrobots,” which can function as mechanical grippers.
What is “necrobotics?”
Using animal features or components to create robotic systems is not a novelty in research.
Think about bio-inspired and biohybrid robots.
In bio-inspired approaches, researchers look to an animal’s physical morphology for design ideas and implement them into complex engineering systems. In biohybrid systems, living or active biological materials serve as the basis for a system that requires careful and precise maintenance.
By reusing dead spiders as mechanical grippers, the Rice University team has taken science one step further. It now uses biotic materials as robotic components, initiating the field of ‘necrobotics’.
Co-author of the study Daniel Preston explains that the team’s lab specializes in soft robotic systems that often use non-traditional materials, as opposed to hard plastics, metals and electronics.
“The spider falls into this line of research,” he says. “It’s something that hasn’t been used before, but has a lot of potential.”
As he noted, the body of a deceased spider is the perfect architecture for small-scale, naturally derived grabs.
Unlike humans and other mammals that move their limbs by synchronizing opposing muscles, spiders use hydraulics.
They only have flexors, which allow their legs to curl inward, and they extend them outward with hydraulic pressure. Internal valves in the spiders’ hydraulic chamber also allow them to operate each leg individually.
When they die, they lose the ability to actively pressure their bodies. That’s why they curl up.
The researchers have found a way to exploit this mechanism.
How did the engineers turn the spiders into robots?
Setting up the spider grab required a single and fairly simple manufacturing step.
The scientists tapped the spiders’ hydraulic chamber with a needle and attached the gripper with superglue. They connected the other end of the needle to one of the lab’s test rigs or a hand syringe. This provided a small amount of air that activated the legs almost immediately.
This allowed them to control all the spider’s legs at the same time.
In the video below, Preston demonstrates how the necrobot spiders work. Mind you, it will probably scare you if you are afraid of spiders.
From a weird experiment to handy tech
The team used wolf spiders and tests showed they could lift more than 130% of their own body weight. They let the grippers manipulate a printed circuit board, move objects and even lift another spider.
They also found that the necrobot could withstand nearly 1,000 open-close cycles before showing signs of wear.
But what can be gained from real-life applications?
“There are a lot of pick-and-place tasks that we can look at, repetitive tasks like sorting or moving objects on this small scale, and maybe even things like assembling microelectronics,” Preston says.
Another application could be using the necrobots to capture smaller insects in nature, as they are naturally camouflaged.
Then comes sustainability. “The spiders themselves are biodegradable,” Preston notes. “So we don’t introduce a large waste stream, which can be a problem with more traditional components.”
The necrobots look like zombie spiders coming back to life – and I certainly wouldn’t want one near me lifting things up. Nevertheless, it is awe-inspiring how the fusion of biology and robotics is transforming modern technology.
You will find the full study here.