It sounds like bad science fiction or anime, but researchers are creating helical-artificial fibrous muscle structured tubular soft actuators. What? Oh, tentacle robot arms. Got it.
The researchers at Westlake University in China found inspiration in elephant trunks. Elephant trunks are entirely devoid of bone but use a tubular muscle structure. By deforming certain muscles, complex motion is possible. After understanding how they work, it was just a matter of making a similar structure from artificial muscle fibers.
The resulting actuator uses smart materials and has eleven different morphing modes — more than other attempts to build similar structures. The fabrication sounds difficult, it involves stretching chemically reactive materials over a form with specific winding angles.
The fibers react to light. Depending on the configuration, the stalk can seek light or avoid light. We were hoping the “Materials and Methods” section would give some ideas of how to do this ourselves, but it looks like you’d need some uncommon liquid crystal materials, and you’d also have to work out some of the details.
Animatronic tentacles are usually complex cable affairs. However, we have seen some soft robots in the past, too.
When you think of robots that were modeled after animals, a brittle star is probably not the first species that comes to mind. Still, this is the animal that inspired [Zach J. Patterson] and his research colleagues from Carnegie Mellon University for their underwater crawling robot PATRICK.
PATRICK is a soft robot made from molded silicone. Each of his five limbs contains several shape memory alloy (SMA) springs which can be contracted through Joule heating thereby causing the limbs to bend. The robot’s control board is sending and receiving commands via Bluetooth Low Energy from a nearby computer. To control PATRICK’s motion the researchers constructed a closed-loop system where an offboard OpenCV based camera system is constantly tracking the robot. As shown in the video below with an average velocity of 1 cm/s, PATRICK’s movement is a bit sluggish but the system is supposedly very robust against uncertainties in the environment.
In the future [Zach J. Patterson et al.] would like to improve their design by giving the robot the ability to grasp objects. Ultimately, also the offboard camera should be replaced with onboard sensors so that PATRICK can navigate autonomously.
Soft robots like artificial jellyfish are especially useful underwater and sometimes almost cross the boundary to organic life.
Continue reading “Underwater Crawling Soft Robot Stays In Shape”
It always seems to us that the best robots mimic things that are alive. For an example look no further than the 3D printed mesh structures from researchers at North Carolina State University. External magnetic fields make the mesh-like “robot” flex and move while floating in water. The mechanism can grab small objects and carry something as delicate as a water droplet.
The key is a viscous toothpaste-like ink made from silicone microbeads, iron carbonyl particles, and liquid silicone. The resulting paste is amenable to 3D printing before being cured in an oven. Of course, the iron is the element that makes the thing sensitive to magnetic fields. You can see several videos of it in action, below.
Continue reading “This 3D Printer Is Soft On Robots”
For many of us, our first robots, or technical projects, were flimsy ordeals built with cardboard, duct tape, and high hopes. Most of us grow past that scene, and we learn to work supplies which require more than a pair of kitchen scissors. Researchers at Carnegie Mellon University and Iowa State University have made a material which goes beyond durable, it can heal itself when wounded. To a small robot, a standard hole puncher is a dire assailant, but the little guy in the video after the break keeps hopping around despite a couple of new piercings.
The researcher’s goal is to integrate this substance into bio-inspired robots which may come to harm in the field. Fish-like robots could keep swimming after a brush with a bit of coral or a curious predator. Robot snakes could keep slithering after a fall or a gravel road.
Of course, robotic simulacrums are not the only ones who can benefit from healing circuitry. Satellites are prey to punctures from errant space debris.
Continue reading “Walk It Off, Healing Robots”
Despite what we may have seen in the new Winnie the Pooh movie, our cherished plush toys don’t usually come to life. But if that’s the goal, we have ways of making it happen. Like these “robotic skins” from Yale University.
Each module is a collection of sensors and actuators mounted on a flexible substrate, which is then installed onto a flexible object serving as structure. In a simple implementation, the mechanical bits are sewn onto a piece of fabric and tied with zippers onto a piece of foam. The demonstration video (embedded below the break) runs through several more variations of the theme. From making a foam tube (“pool noodle”) crawl like a snake to making a horse toy’s legs move.
There’s a serious motivation behind these entertaining prototypes. NASA is always looking to reduce weight that must be launched into space, and this was born from the idea of modular robotics. Instead of actuators and sensors embedded in a single robot performing a specific function, these robotic skins can be moved around to different robot bodies to perform a variety of tasks. Such flexibility can open up more capabilities while occupying less weight on the rocket.
This idea is still early in development and the current level prototypes look like something most of us can replicate and improve upon for use in our projects. We’ve even got a controller for those pneumatics. With some more development, it may yet place among the ranks of esoteric actuators.
Continue reading “Turn Your Teddy Bear Into A Robot With Yale’s “Robotic Skin””
Popcorn! Light and fluffy, it is a fantastically flexible snack. We can have them plain, create a savory snack with some salt and butter, or cover with caramel if you have a sweet tooth. Now Cornell University showed us one more way to enjoy popcorn: use their popping action as the mechanical force in a robot actuator.
It may be unorthodox at first glance, but it makes a lot of sense. We pop corn by heating its water until it turns into steam triggering a rapid expansion of volume. It is not terribly different from our engines burning an air-fuel mixture to create a rapid expansion of volume. Or using heat energy to boil water and trigger its expansion to steam. So a kernel of popcorn can be used as a small, simple, self-contained engine for turning heat energy into mechanical power.
Obviously it would be a single-use mechanism, but that’s perfectly palatable for the right niche. Single-use is a lot easier to swallow when popcorn is so cheap, and also biodegradable resulting in minimal residue. The research paper demonstrated three recipes to harness popping corn’s mechanical energy, but that is hardly an exhaustive list. There’s an open invitation to brainstorm other creations to add to the menu.
Of course, if you prefer candy over popcorn, you could build a robot actuator out of licorice instead.
Either way, the robot uprising will be delicious.
[via IEEE Spectrum]
Continue reading “Hold The Salt And Butter, This Popcorn Is For A Robot”
Blend the Japanese folding technique of Kirigami with an elastomer actuator, and what have you got? A locomoting snake robot that can huff around its own girth with no strings attached! That’s exactly what researchers at the Wyss Institute and Harvard School of Applied Sciences did to build their Kirigami Crawler.
Expanding and contracting propel this crawler forward. As the actuator expands, the hatched pattern on the plastic skin flares out; and when it contracts, the skin retracts to a smoother form. The flared hatch pattern acts like a cluster of little hooks, snagging multiple contact points into the ground. When the skin retracts, these hooks fold back inside while giving the body a slight push forward in the process. It’s a clever tactic, and almost identical to the way real-world snakes propel themselves. In fact, after iterating on a few skin patterns, they found that a trapezoidal pattern, which most closely resembles that of snakeskin, can cover ground fastest.
We’re thrilled to see such authentic biomimicry come to us without any extreme tooling or special molds. Still not satisfied with your share of crawling robots for one day? Have a peek into the past, and indulge yourself with a sine-wave locomotion.
Thanks for the tip, [Olivia]!
Continue reading “Papercraft-Inspired Snake-bot Slithers Like A Real One”