Ostriches are the largest two-footed bird. While they are unable to fly, they are the fastest running birds in the world, reaching speeds of up to 43 mph. But how are these large birds able to reach such fast speeds? Understanding the kinematics of ostrich motion compared to humans can reveal to us important information that can help when designing human-based technologies.
Continue reading “Ostrich-ized From Flight, But Not From Stride: The Unique Biomechanics of the World’s Fastest Bird”Tag: land animals
The 21,000 lb Question – How Elephants Defy Logic Through Locomotion
One of the most prominent questions in the engineering industry is how to build something that lasts. The biomechanics of elephant locomotion gives an example of near engineering perfection stemming from biology itself – with each foot supporting thousands of pounds of weight consistently and without failure while also maintaining mobility.
Continue reading “The 21,000 lb Question – How Elephants Defy Logic Through Locomotion”Goats Defying Gravity
This video describes how mountain goats can influence robot design based on the biomechanical principles that influence their impeccable balance. It explains how a mountain goat’s center of mass, controlled limb force generation, and specialized hoof anatomy can all be mimicked in robotics and why it is relevant.
Credits:
- Animaker video animation software.
- ETH Zurich. The snake that saves lives
- National Geographic. Amazing footage: Goats climbing on a near-vertical dam
- Ferguson, N. The Dingo: A low cost, open-source robot quadruped
- Abad, Sara-Adela, et al. (2019). Significance of the Compliance of the Joints on the Dynamic Slip Resistance of a Bioinspired Hoof. IEEE Transactions on Robotics, 35(6), 1450–1463. https://doi.org/10.1109/TRO.2019.2930864
- Ranjan, Alok, et al. (2024). Design Guidelines for Bioinspired Adaptive Foot for Stable Interaction With the Environment. IEEE/ASME Transactions on Mechatronics, 29(2), 843–855. https://doi.org/10.1109/TMECH.2023.33…
- Sombolestan, Mohsen, et al. (2021). Adaptive Force-Based Control for Legged Robots. In 2021 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (pp. 7440–7447). IEEE. https://doi.org/10.1109/IROS51168.202…
- Lewinson, Ryan T., and Darren J. Stefanyshyn. (2016). A Descriptive Analysis of the Climbing Mechanics of a Mountain Goat (Oreamnos Americanus). Zoology, 119(6), 541–546. https://doi.org/10.1016/j.zool.2016.0…
- Tian, Weijun, et al. (2022). The Limb Kinetics of Goat Walking on the Slope with Different Angles. Biomimetics, 7(4), 220. https://doi.org/10.3390/biomimetics70…
How Goats Defy Gravity and How it Has Inspired Engineers
In the world of engineering, the optimization of prosthetics and robotics is at the forefront of research. However, many designs are faced with the same problem – poor stability, especially when it comes to rough or sloped surfaces. This prevents amputees from being able to enjoy outdoor activities such as hiking and rock climbing, and traversing robots from being able to perform complex search and rescue. So, researchers have gotten creative and have decided to look into nature. Naturally, mountain goats became a prime source of inspiration due to their ability to seemingly defy gravity when scaling mountain tops. How do they do this? To answer this question, plenty of research has been conducted to look into things like goat anatomy, joint angles, centers of mass, ground reaction forces, and more.
Continue reading “How Goats Defy Gravity and How it Has Inspired Engineers”Springing Squirrels: The Mechanics of Squirrel Leaping and Landing
How do squirrels escape dogs, scavenge for food, and climb their way around trees? The answer is simple: squirrel parkour. With precise calculations and the physical ability to maneuver and adjust, squirrels can effortlessly leap from tree branch to tree branch without falling.
A study done by Nathaniel Hunt et al. tested squirrels on different activities where gap distance, flexibility of the launching bar, and gap height were varied. The squirrels were observed, and results showed a consistent trade-off scenario between branch flexibility and leap distance. When on high-flexibility branches, squirrels jumped closer to the branch connection point. This led to large gap lengths, up to three times the squirrel’s body length. The opposite was true for low-flexibility branches. Squirrels are able to determine branch flexibility and what launch point is necessary for them to safely make leaps to neighboring branches.
In terms of safety, throughout the course of the experiments, the researchers observed that not a single squirrel fell. They were able to successfully adjust to varying branch flexibility, height, and leap distance. The squirrels were able to accomplish this feature by performing a “parkour” move. The squirrels jumped off the branch toward a nearby wall and sprang off of it before landing. The squirrels utilized this parkour move to adjust their landing speeds. Not only does this demonstrate the adaptability of squirrels, but also their ability to adjust their bodies while jumping.
An important concept to consider when looking at mechanics of squirrels jumping is the force and speed at which they take off. Grégoire Boulinguez-Ambroise et al. completed a study to examine the effects of different branch sizes on squirrel take-off velocity and the displacement of their center of mass. Results showed that there was a difference between squirrels jumping upwards off of a flat plate, and off of a branchlike object. When jumping off the branchlike poles, squirrels prioritized shifting their center of mass to jump, whereas on the flat plates, priority was given to the produced force. These results imply that while on branches, squirrels try to maximize balance before jumping. This intuitively makes sense as you would want to be as balanced as you could before making a leap!
Interesting results, shown in Figure 1, showed that squirrels jumped the highest while jumping from the smaller diameter branch, and jumped the lowest when jumping from flat ground. Putting this together with the previously mentioned idea of squirrels shifting their center of mass, squirrels are able to adjust their approach to jumping depending on branch sizes.
Based on the size of the branch, squirrels have to adjust their feet position. For smaller branches, squirrels must place the middle of their feet closer to the sides of the branch. Figure 2 shows the forces acting between the feet and the branch. Varying branch sizes will change the angles and size of the forces, and the squirrel will have to adjust accordingly. In the study mentioned above, results showed that the feet placement on the varying diameter sizes did not have a significant impact on the measured take-off velocity. This implies how squirrels can adjust to different sized branches and still maintain high quality jumping performance.
Diving into how squirrels jump, they use their hind limbs to push themselves off of an object. Richard Essner completed a study on squirrel launch kinematics. Results showed that for leaping, squirrels act as small-bodied primates and rely less on their knees than their ankles. Squirrels also use their tails to help with balance.
While squirrels may seem like cute animals who only care about adding to their nut collection, there is a lot more than meets the eye when it comes to their movement between and through trees. The nature of squirrels to be able to apply the parkour move, change foot placement, determine the flexibility of branches, and adjust take-off velocity depending on each individual branch they leap from are just a few of the amazing features that squirrels can accomplish.
Feature image from Pixabay.
The Biomechanical Blueprint: How Cheetahs’ Bodies Are Engineered for Speed
The cheetah (Acinonyx jubatus) is the fastest land animal on earth reaching speeds of over 60 miles per hour (29 m/s). The cheetah is native to Africa and parts of the Middle East and is a predator of the impala, along with several other prey animals of the Savannah and Middle East. The biomechanics of the cheetah can help us understand how to create such high speeds in biological organisms and how to protect the body against high acceleration and decelerations.
Read more: The Biomechanical Blueprint: How Cheetahs’ Bodies Are Engineered for Speed Continue reading “The Biomechanical Blueprint: How Cheetahs’ Bodies Are Engineered for Speed”How Do Chameleons Catch Food with Their Tongues?
Have you ever wondered how chameleons are able to shoot out their tongues, grab a snack, and bring it back to their mouths? That skill is all thanks to the chameleon tongue’s unique mix of special muscles. Their ability to use their tongue for grocery shopping is essential for their survival, and the way it works is fascinating!
Continue reading “How Do Chameleons Catch Food with Their Tongues?”Move Over Band-Aids, the Gecko is Here.
Band-Aids and stitches have been around forever. They are safe and common ways to address everything from paper cuts to deep wounds. However, these technologies each have their own drawbacks and researchers have looked to nature to improve upon them; enter the gecko, more specifically their feet. The goal of these scientists was to use the adhesive properties of a gecko’s foot pads as an alternative method to hold wounds closed, but how does this work?
What Makes Geckos so Clingy?
A gecko’s foot pads are unique instead of relying on any sticky substance, their toes have rows and rows of setae. Setae as you can see below are essentially rows of microscopic hooks that can cling in one direction. This causes no damage to the surface and because of the ways the setae are oriented, they are easy to remove from the surface in one direction. This is what allows a gecko to both cling to and easily remove their feet from a surface, or in our case makes adhesives made with this technique both secure and easier to remove than their counterparts.
The Importance of Stickiness
Human skin is actually quite a rough surface that undergoes a lot of compression, tension and is further complicated by the existence of hair follicles and sweat. All of these factors make attaching anything like the gecko-based dry adhesive to the skin a daunting task. To get around this, bandaids rely on overpowering amounts of sticky substance and stitches are woven into the skin. This means that upon removal more damage and irritation to the wound can occurs. In a study the adhesive force of this technology was tested as well as the removal difficulty. It was found that this new method can achieve maximum closing forces slightly below that of sutures and is easier to remove than a bandaid of the same size. Notably, it does perform worse in wet or very humid conditions, so waterproof band-aids have a bright future.
The Design
A team of researchers published a study outlining the design, benefits, and drawbacks of a medical adhesive designed to mimic the gecko. This design encompasses the wound while providing a closing force to keep the wound closed. The amount of closing force imparted can be altered by changing both the number of legs and their thickness.
This is important because it means this method can be adapted to match the type of wound it is addressing. For a small cut a small adhesive with few legs can be used whereas, for a more serious wound, a larger adhesive layer with more, thicker legs will be used. This method also allows for air circulation allowing oxygen to reach to wound which promotes healing better than traditional methods. Using a gecko adhesive also minimizes wound irritation which can be a problem, especially for stitches and sutures which often cause irritation and even infection. Finally, this dry adhesive surface is biocompatible and can be made biodegradable. This means they will not react negatively with the skin and can safely dissolve in the body. This makes it a very desirable alternative to sutures which must be removed after insertion causing further wound irritation and requiring another visit to the doctor.
So while it may take a few years still don’t be surprised if you see dry adhesives for wound closings popping up on shelves; and when you see them know that they were inspired by the gecko. If you would like to learn more keep reading here.
You’re One Tough Nut To Crack!
On April 13, 2022, a video uploaded to YouTube titled The End broke the internet. A former Blue Sky Studios Employee, who over the years helped animate the Ice Age movie franchise, posted an unreleased short scene that depicted Scrat, the crazed squirrel from the series, finally catching and eating the acorn he spent more than a decade fighting and almost perishing over.
Continue reading “You’re One Tough Nut To Crack!”Avoiding Cat-astrophe: How do Cats Land their Crazy Jumps?
Cats always land on their feet, or so the saying goes. Every cat owner has witnessed their feline make death defying jumps and walk away like it’s no big deal. 90% of cats can actually survive falling off of a high rise building. But how do they do it? How do cats absorb the impact of their leaps without sustaining injuries?
Continue reading “Avoiding Cat-astrophe: How do Cats Land their Crazy Jumps?”