Watch researchers use dead spiders as robotic grippers

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Well, here’s something you don’t see everyday. Engineers at Rice University are turning dead spiders into mechanical grippers. The dead wolf spiders are being tested to show they can reliably lift more than 130% of their own body weight. The researchers said this is the first step toward a novel area of research they call “necrobotics.”

According to the researchers, unlike people and other mammals that move their limbs by synchronizing opposing muscles, spiders use hydraulics. A chamber near their heads contracts to send blood to limbs, forcing them to extend. When the pressure is relieved, the legs contract. Internal valves in the spiders’ hydraulic chamber, or prosoma, allow them to control each leg individually.

Watch the video at the top of this page to see a demo of the technology.

“The dead spider isn’t controlling these valves,” said Daniel Preston, assistant professor of mechanical engineering, Rice’s George R. Brown School of Engineering. “They’re all open. That worked out in our favor in this study, because it allowed us to control all the legs at the same time.”

To control the legs of a dead spider, the researchers tap into the prosoma chamber with a needle, attaching it with a dab of superglue. The other end of the needle is connected to one of the lab’s test rigs or a handheld syringe, which delivers a minute amount of air to activate the legs almost instantly.

An illustration shows the process by which Rice University mechanical engineers turn deceased spiders into necrobotic grippers, able to grasp items when triggered by hydraulic pressure. | Credit: Preston Innovation Laboratory

The lab ran one dead spider through 1,000 open-close cycles to see how well its limbs held up, and found it to be fairly robust.

“It starts to experience some wear and tear as we get close to 1,000 cycles,” Preston said. “We think that’s related to issues with dehydration of the joints. We think we can overcome that by applying polymeric coatings.”

This lab at Rice University specializes in soft robotic systems that often use non-traditional materials, like dead wolf spiders, as opposed to hard plastics, metals and electronics.

“This area of soft robotics is a lot of fun because we get to use previously untapped types of actuation and materials,” said Preston. “The spider falls into this line of inquiry. It’s something that hasn’t been used before but has a lot of potential.”

You can read the lab’s peer-reviewed research here to learn more information about necrobotics.