A spider "resurrected from the dead" and turned into a claw machine in seconds? This study is a bit "weird and interesting"

A dead spider slowly descends, and then, suddenly, it "comes back to life" - spreading its eight long legs and tightly grasping another dead spider.

Can be picked up and put down | References [1]

Can you believe it? This is a new type of robot, but it is made from a special material - spider corpses.

The method of manipulating the spider's body is not difficult. You just need to stick a needle into the spider's body and pump air into it, so that the originally curled up dead spider can stretch its legs outward. When the pressure in the spider's body is released, its legs will close and grab the target object.

Put the needle into the dead spider first | Brandon Martin

This dead spider version of the claw machine was created by a research team from the Department of Mechanical Engineering at Rice University in the United States. Daniel Preston, the team leader and assistant professor of mechanical engineering, said that this is the first time that a complete animal has been used to make a robot.

In September this year, their research also won the Ig Nobel Prize in Mechanical Engineering.

2023 Ig Nobel Prize - Mechanical Engineering

Dead Spider: Why me?

"It's understandable that many people would feel uncomfortable seeing spiders, but from an engineering perspective, spiders' locomotion mechanics are very interesting," said Te Faye Yap, a doctoral student in mechanical engineering at Rice.

Her research on dead spiders began in 2019, shortly after the establishment of the Preston Innovation Lab at Rice University. While cleaning up in the lab, Ye Defei noticed a dead spider curled up in the hallway. She and her colleagues were curious about why spiders curl up their legs when they die.

When spiders die, their legs curl up | Rice University

So everyone immediately looked up information online and found that "spiders don't have the antagonist muscle combination of biceps and triceps like humans do," said Ye Defei. "They only have flexor muscles that allow the legs to curl inward and hydraulic pressure to extend the legs outward. When they die, they lose the ability to actively pressurize their bodies. That's why they curl up. "

"This is so interesting! We hope to find a way to exploit this mechanism," said Ye Defei.

How to "revive" a dead spider?

——Cheer it up

After understanding the reason why spiders curl up after death, everyone has a new question - can compressed air be used to regain control of the legs of dead spiders?

So they picked up the spider corpse. In addition to the spider corpse, the experimental materials used also included a syringe and super glue. The researchers first inserted the needle into the spider's cephalothorax, and then used a little super glue to seal the gap around the needle. After connecting the syringe, the researchers were able to pressurize the spider's hydraulic chamber through the syringe.

Insert the needle of the syringe into the spider's cephalothorax and drip a little glue | Reference [1]

When air is pumped in to increase pressure, the dead spider's legs immediately activate and open outwards, while when the pressure is reduced, the legs naturally contract and close under the action of the flexor muscles.

Controlling hydraulic pressure in a spider's body with a syringe | References [1]

Invertebrates such as spiders have hemolymph in their bodies, which is similar to the blood in vertebrates. Hemolymph is like a hydraulic system. When air is injected, the hemolymph is pressurized, which in turn causes the pressure on the spider's leg joints to increase. The researchers also found that the chemical composition of the spider's hemolymph did not change significantly one hour after death, or even seven days after death.

In the experiment, in order to observe the endurance of spider legs, a dead spider opened and closed its legs nearly 1,000 times, which was quite tough. Later, its leg joints began to show some wear and tear. "We think this is related to joint dehydration, and we can solve this problem by applying a polymer coating," Preston said.

The experiment found that spider corpses without any coating could only be used as claw machines for two days, while spider corpses coated with beeswax could effectively prevent dehydration and have a longer "lifespan". The researchers said that they would conduct further research on different coating materials.

Detail of the spider's leg joints | Reference [1]

Although the dead spider can open and close its legs continuously, it has not really been resurrected or turned into a zombie. Preston said: "We are sure it is inanimate."

Catch a giant spider heavier than yourself

In experiments, the dead spider was able to grab several different objects, such as removing jumper wires on a breadboard to disconnect an LED, picking up a piece of polyurethane foam dyed red, and even picking up another large spider that was 1.3 times its weight.

Grab the jumper wires on the breadboard | References [1]

So the researchers thought, do spiders of different sizes have different gripping powers?

By studying spiders of different sizes, they found that small spiders (10 mg jumping spiders) can exert a gripping force of twice their body weight, while larger spiders (such as the Goliath bird-eating spider, which weighs about 200 grams) can only grasp objects that are 10% of their body weight - but still, that's 20 grams!

Analyzing the gripping power of spiders of different sizes | References [1]

More environmentally friendly and more convenient

The researchers named this groundbreaking research field Necrobotics, where Necro means corpse or death, and robotics means robot or robotics.

Research in this area could lead to biodegradable grippers for very small objects, which are more environmentally friendly than other robotic parts and do not generate electronic waste.

A jig made from a spider carcass | Preston Innovation Lab

Soft robotics is the focus of Preston's lab. The design and manufacture of traditional rigid robots usually requires complex and tedious processes, while soft robots can save some of these complex manufacturing requirements. The dead spider robot gripper is even more convenient. "We don't need to build this pneumatically driven gripper from scratch, we just need to use nature," Preston said.

In addition to being environmentally friendly, spiders are plentiful, so it's easy for researchers to collect them. Unfortunately, the researchers say they can't yet guarantee that no spiders were harmed during the experiment. The spider carcasses used in the study were obtained by euthanasia (freezing them at about -4°C for 5 to 7 days). Existing research literature does not provide clear guidance on how to ethically and humanely purchase and euthanize spiders.

The study was published in Advanced Science last July | References [1]

Further work over the past year has allowed the researchers to more precisely control the spider's body - by driving just one leg, rather than all eight .

References

[1] Yap, TF, Liu, Z., Rajappan, A., Shimokusu, TJ, & Preston, DJ (2022). Necrobotics: Biotic Materials as Ready-to-Use Actuators. Adv. Sci., 9(29), 2201174. doi: 10.1002/advs.202201174

[2] University, R. (2022, July 25). Lab manipulates deceased spiders' legs with a puff of air to serve as grabbers. Youtube. Retrieved from https://www.youtube.com/watch?v=1JOS6hMHIUM

[3] Rice engineers get a grip with 'necrobotic' spiders. (2023, October 25). Retrieved from https://news.rice.edu/news/2022/rice-engineers-get-grip-necrobotic-spiders

[4] Preston, four others win Ig Nobel Prize for 'necrobotic' spider study. (2023, October 25). Retrieved from https://news.rice.edu/news/2023/preston-four-others-win-ig-nobel-prize-necrobotic-spider-study

[5] Regina G. Barber, AO (2023). Why scientists are reanimating spider corpses for research. NPR. Retrieved from https://www.npr.org/2023/10/18/1198908301/necrobotics-reanimating-spiders-ig-nobel-prize

[6] Osborne, M. (2022). Scientists Use Dead Spiders as Claw Machines. Smithsonian Magazine. Retrieved from https://www.smithsonianmag.com/smart-news/scientists-use-dead-spiders-to-grip-objects-180980498

[7] Regina G. Barber, AO (2023). Why scientists are reanimating spider corpses for research. NPR. Retrieved from https://www.npr.org/2023/10/18/1198908301/necrobotics-reanimating-spiders-ig-nobel-prize

Planning and production

Source: Bringing Science Home (id: steamforkids)

Author: Cloud, editor of Everything Magazine

Reviewer | Ziv, editor of "Everything" magazine

Editor: Yinuo