[♪ INTRO].

Billions of years of evolution  has resulted in organisms with oodles of clever and super-efficient adaptations, many of which are better than anything  we’ve ever been able to engineer. Fortunately, we’re not above, you know, borrowing from nature to do the  important work of saving human lives.

And few fields have benefited more from  ripping off the animal kingdom than surgery. So, if you ever find yourself recovering  from a trip to the operating room, you might have one of these six nature-inspired  surgical breakthroughs to thank. Let’s start with a common category of procedures: getting something inside of you out.

See, surgeons often need to remove  small bits of the human body. This could be for a biopsy, which is a  tissue sample taken for testing, or because there’s something in there that doesn’t  belong, like diseased tissue or a blood clot. To do this, they use a device  called a tissue extractor.

Current tissue extractors rely on  suction, but that’s not super efficient. They’re prone to getting clogged, and the  technology limits how small they can be. Suction-based devices also  don’t do a very good job of pulling tissue through long tubes.

That means they can’t be used to remove  tissue in the most well-buried parts of the human body, such as  tumors deep inside the brain. They’re also not especially gentle. A suction-based tissue extractor  may harm surrounding tissue, especially if it accidentally sucks  up something it isn’t supposed to.

So, to try and improve on this, engineers  are working on a new kind of extractor based on the egg-laying organ of a parasitic wasp. That organ is kind of like the bit of tube that goes into your vein  when you’re receiving an IV. Called an ovipositor, this tiny egg-laying  structure is thin, hollow and flexible.

But what’s really clever about it is that  it’s lined with tiny blade-like structures that interlock like a three-dimensional puzzle. The blades move independently, but work together to guide  each egg to its destination. And now, scientists have created  a prototype tissue extractor inspired by the wasp ovipositor.

The device is described in a 2020 paper, and it’s a tube made from a bundle  of six semi-cylindrical blades. The blades slide forwards and  backwards and, as they move, they sort of nudge the tissue up the tube. Researchers hope this device will  help reduce trauma during surgery, allowing surgeons to remove tissue from  places that aren’t usually easy to get to.

At the moment, the primary drawback  is that the device is anywhere from 50 to more than 150 times  slower than a suction device, so it’s not great for jobs  where speed is a major concern. Still, the team that developed the  device does think they can speed it up by redesigning the inside of the  tube or tweaking the motor’s design, so there’s still work to be done. Mosquitoes carry diseases, and  they’re also just plain annoying.

But they do have some redeeming  qualities—even for medicine. The proboscis of a mosquito  is serrated and super-sharp, so when she sticks you with it, there’s less  contact with your tissue and less overall force than there is when you get stuck  by, say, a nurse giving you a flu shot. That’s why you can’t even always feel  when a mosquito bites you: it only becomes obvious after she’s taken what she wants  and is trying to make a clean getaway.

Meanwhile, some injections can be painful,  so it would be great if we could find a similarly painless way to deliver  medication or take a blood sample. The key seems to be reducing  the amount of resistance as the needle penetrates tissue. So, using the mosquito proboscis  as inspiration, scientists created a three-part needle and published  their progress in another 2020 study.

The two outer needles are based on maxillae— the needles that mosquitoes use to pierce flesh. And these needles have been etched  by a machine to make them jagged. Meanwhile, the center needle is straight.

It’s based on the labrum,  which is the mosquito mouthpart that penetrates blood vessels. The needles move independently but cooperatively, the way a mosquito's proboscis does. And tests conducted during this study  found that the independent motion of the three needles, combined  with the jagged notches, were effective in reducing tissue  displacement in the test material.

That means it should also  reduce pain in real life. It’s not clear when we’ll see this  tech roll out into the real world, but I am looking forward to that day! Animals aren’t the only species  in nature that inspire us.

We can also learn something from plants, too. Like, when a cucumber tendril touches something, tactile sensors on the tendril induce it to coil, which anchors the plant securely to  whatever object the tendril has encountered. And doctors sometimes use  tendril-like devices, too.

Called robotic manipulators,  these devices allow a surgeon to operate on an internal body part without  the need to create a large, invasive cut. The problem with these surgical devices  is that they’re not super flexible, and it can be hard to steer them  around sensitive organs and tissues. So in 2014, researchers decided to  try to improve on current designs with cucumber-inspired tech.

The idea is to add a bunch of tiny sensing devices to the surface of the robotic manipulator. When these sensors encounter  something, like a bone or organ, they can measure the amount of pressure. Then, they can use that info  to make automatic adjustments or just provide feedback so the  surgeon can decide what to do next.

A robotic manipulator with sensors like  this could make minimally-invasive surgery even less risky. It would minimize the  risk of injuring tissue during a collision or accidentally severing something  that isn’t supposed to be cut. All thanks to cucumbers.

Next, one of the holy grails of surgery is a glue that can keep stuff stuck together  in our warm, wet, squishy insides. Which sounds kind of similar  to the underwater environments inhabited by some marine and freshwater mussels. To stop themselves from drifting away, these creatures make unique  structures called byssal threads, which keep them securely anchored  to rocks and other surfaces.

To make the threads, a  mussel’s byssal gland secretes a collection of proteins that form sticky tethers. The really cool thing about byssal threads  is that the mussel can remain attached to rocks, other mussels, boat bottoms, or whatever, even underwater and in the  presence of strong surf. And researchers are especially interested in developing a glue like that for fetal surgery.

Surgery in the womb is very tricky because if the incision breaks open  afterwards, the results can be tragic. If amniotic fluid leaks  through a ruptured incision, it can lead to early labor and premature birth. So, during fetal surgery, a mussel-inspired glue could pre-seal the fetal membrane  before an incision is made.

Surgeons would use it to make a sort of  patch between the uterine wall and the fetal membrane, before making  the incision through that patch. That would create a watertight seal  around the surgical instruments, and help stabilize the incision during surgery. Researchers began developing this glue in 2010, and it’s based on something called DOPA, an amino acid residue found  in the mussel’s foot proteins.

It’s still a work in progress, though—designers  are continuing to perfect the formula with other mussel-inspired sticky substances. But so far, it’s a really clever idea. Like, who would have thought I’d say  “mussel-inspired glue” and “fetal surgery” in the same sentence?

Pomphorhynchus laevis is a  parasitic worm that preys on fish. It has a head that looks  kind of like a barrel cactus, and it uses these spines to anchor  itself to the tissue of its host. Then, its head gets bigger until it  becomes sort of plug-like.

Which sounds just horrible for the fish, but guarantees  a secure attachment for the worm. And researchers are hoping they can copy  this trick to make skin grafts less horrible. Skin grafts are notoriously painful  and can go wrong in a lot of ways.

Staples and stitches hurt, can damage  tissue, they’re prone to infection... And stapling around the edges isn't  always super effective because, if the graft doesn't stay flush  with the tissue it's covering, then fluid can fill in the space  underneath it and cause the graft to fail. So, scientists were inspired by  Pomphorhynchus’ mode of attachment when they designed this new  skin graft technology in 2013.

Researchers added tiny cone-shaped  needles to the surface of the graft, each one less than half a  millimeter wide at the base. Their small size helps them  penetrate tissue gently, as opposed to the way that larger  staples make quick, violent punctures. And when they contact water, the needles swell.

That locks them securely into place,  just like the worm’s head does. Since there are a lot of them,  the graft usually stays flush, which further reduces the risk of complications. They’re a lot easier and less  painful to remove than staples, too, since the swelling process is totally reversible.

So—and it feels weird to say  this—thanks, worm parasite! Finally, contrary to popular belief, geckos  don't have anything sticky on their feet, and they don't have little suction  cups on their toes, either. And, yet, geckos can be found attached  securely to almost any surface.

Which would be a great attribute for a bandage. What gecko feet do have is a series  of tiny structures called spatulae. The spatulae are arranged on each of the  millions of tiny hairs, called setae, that cover the bottoms of the gecko’s feet.

There’s nothing chemical happening  with the spatulae and the setae— it’s all about geometry. When the gecko puts its foot down, the  setae and spatulae come into very close contact with the contours of whatever  surface the gecko is climbing. This creates a kind of electrostatic  connection between the molecules of the foot hairs and the molecules  of the surface material.

The result: sticky feet. Minus the glue. Bandages that could do something  similar would be pretty useful.

Surgeons could use them to wrap up wet  surfaces like those inside a human body. Imagine wrapping an intestine the  way you might bandage a finger. To make a bandage that could do  this, you need a material that sticks but is also biodegradable, flexible,  and doesn’t cause inflammation.

So in 2008, designers used a rubber-like  substance to create a bandage with the texture of a gecko’s foot,  and made just a little bit stronger with a layer of sugar-based glue. These bandages can be folded, which  means they can be inserted through very small incisions made during  minimally-invasive procedures. And because it’s biodegradable, the  bandage doesn’t have to be removed.

That makes it ideal for things  like gastrointestinal surgery,   or repairing ulcer damage in the stomach. Overall, humans are pretty clever inventors,  so it’s kind of humbling to think that nature was able to devise solutions  to so many of our problems before we even knew what those problems were. Also, it’s a reminder that basic research— like how parasitic wasps deposit their eggs— can sometimes have huge,  totally unexpected payoffs.

Speaking of pokey, stabby things like ovipositors…. There are only a few days left  to get our pin of the month! Every month, we release a new pin  inspired by an amazing space mission, and this month, it’s

SOHO: the  Solar and Heliospheric Observatory! If you want to learn about the mission, you can head over to SciShow Space after this. And if you want the pin, you’ll only be  able to get it until the end of December! So you can find it at DFTBA.com/SciShow. [♪ OUTRO].