Why bother designing your own robots when you can reuse what nature created?
That was the thought process behind a research project by Rice University engineers that successfully turned dead spiders into robotic grasping claws. Scientists have dubbed the new field of research “necrobotics” and say it could create cheap, effective and biodegradable alternatives to existing robotic systems.
But why spiders? While humans use pairs of antagonistic muscles, such as the biceps and triceps, to move their limbs, spiders’ legs have only one flexor muscle that pulls the leg inward. This is countered by a hydraulic system: a chamber in the center of the spider’s body (known as the prosoma) pushes fluid to open the leg, and there are separate valves that allow the animal to control each limb independently. By the way, spiders always curl up when they die; there is no pressure in the system to resist the flexor muscles of the legs.
Armed with this knowledge, the Rice University team discovered that they could artificially control this hydraulic system simply by injecting a needle into a dead spider’s prosoma, pumping air in and out to open and close the spider’s legs like an arcade claw machine.
You can watch a video of their work below:
“It just so happens that the spider is a perfect architecture for small-scale, natural-origin scavengers after it dies,” said Daniel Preston of Rice’s George R. Brown School of Engineering. press release. Spiders can lift more than 130 percent of their body weight and go through 1,000 on-and-off cycles before joint damage.
There is a Rice University team led by graduate student Faye Yap published an article describing their work in the magazine Advanced Science. There, they note, humans have a long history of repurposing the remains of dead organisms for new uses—from animal skins worn as clothing to bones sharpened into arrowheads and tools. In this context, turning a dead spider into a robot catcher is not as unusual as it might first seem.
Scientists also note that roboticists often draw inspiration from the natural world for their designs. the sticky surface of geckos’ feet gold fishtail undulations, for example. But they thought, why copy when you can steal? Mother Nature in particular has worked hard to develop effective mechanisms through millions of years of evolution.
As they wrote in the paper, “The concept of necrobotics proposed in this study utilizes unique designs created by nature that may be difficult or even impossible to replicate artificially.”
:no_upscale()/cdn.vox-cdn.com/uploads/chorus_asset/file/23906354/0718_NECRO_1_WEB.jpeg)
The group ordered test subjects from a biological supply company, reports Gizmodo, which caused some problems for their arachnophobic counterparts. According to a release by Rice’s Preston, “One of our front office employees really doesn’t like spiders. So when another delivery arrived for us to use for the project, we had to call the front office and just let them know.
The work is essentially a proof of concept for now, but Preston said it could have many applications in the future. “There’s a lot of pick-and-place, repetitive tasks like sorting or moving objects at this small scale, and maybe things like assembling microelectronics,” he said in a press release.
Another use could be collecting animal specimens in the wild, Yap said, adding that the spider hunter is “naturally camouflaged.”