Judgement Day Update: Super-Strong Robotic Muscle

robot-arm-wrestling-03-20-09In their quest to build better, smarter and faster machines, researchers are looking to human biology for inspiration. As has been clear for some time, anthropomorphic robot designs cannot be expected to do the work of a person or replace human rescue workers if they are composed of gears, pullies, and hydraulics. Not only would they be too slow, but they would be prone to breakage.

Because of this, researchers have been working looking to create artificial muscles, synthetics tissues that respond to electrical stimuli, are flexible, and able to carry several times their own weight – just like the real thing. Such muscles will not only give robots the ability to move and perform tasks with the same ambulatory range as a human, they are likely to be far stronger than the flesh and blood variety.

micro_robot_muscleAnd of late, there have been two key developments on this front which may make this vision come true. The first comes from the US Department of Energy ’s Lawrence Berkeley National Laboratory, where a team of researchers have demonstrated a new type of robotic muscle that is 1,000 times more powerful than that of a human’s, and has the ability to catapult an item 50 times its own weight.

The artificial muscle was constructed using vanadium dioxide, a material known for its ability to rapidly change size and shape. Combined with chromium and fashioned with a silicone substrate, the team formed a V-shaped ribbon which formed a coil when released from the substrate. The coil when heated turned into a micro-catapult with the ability to hurl objects – in this case, a proximity sensor.

micro_robot_muscle2pngVanadium dioxide boasts several useful qualities for creating miniaturized artificial muscles and motors. An insulator at low temperatures, it abruptly becomes a conductor at 67° Celsius (152.6° F), a quality which makes it an energy efficient option for electronic devices. In addition, the vanadium dioxide crystals undergo a change in their physical form when warmed, contracting along one dimension while expanding along the other two.

Junqiao Wu, the team’s project leader, had this to say about their invention in a press statement:

Using a simple design and inorganic materials, we achieve superior performance in power density and speed over the motors and actuators now used in integrated micro-systems… With its combination of power and multi-functionality, our micro-muscle shows great potential for applications that require a high level of functionality integration in a small space.

In short, the concept is a big improvement over existing gears and motors that are currently employed in electronic systems. However, since it is on the scale of nanometers, it’s not exactly Terminator-compliant. However, it does provide some very interesting possibilities for machines of the future, especially where the functionality of micro-systems are concerned.

graphene_flexibleAnother development with the potential to create robotic muscles comes from Duke University, where a team of engineers have found a possible way to turn graphene into a stretchable, retractable material. For years now, the miracle properties of graphene have made it an attractive option for batteries, circuits, capacitors, and transistors.

However, graphene’s tendency to stick together once crumpled has had a somewhat limiting effect on its applications. But by attacking the material to a stretchy polymer film, the Duke researchers were able to crumple and then unfold the material, resulting in a properties that lend it to a broader range of applications- including artificial muscles.

robot_muscle1Before adhering the graphene to the rubber film, the researchers first pre-stretched the film to multiple times its original size. The graphene was then attached and, as the rubber film relaxed, the graphene layer compressed and crumpled, forming a pattern where tiny sections were detached. It was this pattern that allowed the graphene to “unfold” when the rubber layer was stretched out again.

The researchers say that by crumpling and stretching, it is possible to tune the graphene from being opaque to transparent, and different polymer films can result in different properties. These include a “soft” material that acts like an artificial muscle. When electricity is applied, the material expands, and when the electricity is cut off, it contracts; the degree of which depends on the amount of voltage used.

robot_muscle2Xuanhe Zhao, an Assistant Professor at the Pratt School of Engineering, explained the implications of this discovery:

New artificial muscles are enabling diverse technologies ranging from robotics and drug delivery to energy harvesting and storage. In particular, they promise to greatly improve the quality of life for millions of disabled people by providing affordable devices such as lightweight prostheses and full-page Braille displays.

Currently, artificial muscles in robots are mostly of the pneumatic variety, relying on pressurized air to function. However, few robots use them because they can’t be controlled as precisely as electric motors. It’s possible then, that future robots may use this new rubberized graphene and other carbon-based alternatives as a kind of muscle tissue that would more closely replicate their biological counterparts.

artificial-muscle-1This would not only would this be a boon for robotics, but (as Zhao notes) for amputees and prosthetics as well. Already, bionic devices are restoring ability and even sensation to accident victims, veterans and people who suffer from physical disabilities. By incorporating carbon-based, piezoelectric muscles, these prosthetics could function just like the real thing, but with greater strength and carrying capacity.

And of course, there is the potential for cybernetic enhancement, at least in the long-term. As soon as such technology becomes commercially available, even affordable, people will have the option of swapping out their regular flesh and blood muscles for something a little more “sophisticated” and high-performance. So in addition to killer robots, we might want to keep an eye out for deranged cyborg people!

And be sure to check out this video from the Berkley Lab showing the vanadium dioxide muscle in action:


Source:
gizmag.com, (2)
, extremetech.com, pratt.duke.edu

Judgement Day Update: Artificial Muscles for Robots

artificial-muscle-1It’s a science fiction staple, the android or humanoid robot opens up its insides to reveal a network of gears or brightly-lit cables running underneath. However, as the science behind making androids improves, we are moving farther and farther away from this sci-fi cliche. In fact, thanks to recent advancements, robots in the future may look a lot like us when you strip away their outer layers.

It’s what is known as biomimetics, the science of creating technology that mimics biology. And the latest breakthrough in this field comes from National University of Singapore’s Faculty of Engineering where researchers have developed the world’s first “robotic” muscle. Much like the real thing, this artificial tissue extends to five times its original length, has the potential to lift 80 times its own weight.

???????????????????????In addition to being a first in robotics, this new development is exciting because it resolves a central problem that has plagued robots since their inception. In the 1960s, John W. Campbell Jr, editor of Analog Science Fiction magazine, pointed out this problem when he outlined a scenario where a man is chased across rough country by a mad scientist’s horde of killer robots.

In this scenario, the various models that were chasing the man were stymied by obstacles that the he could easily overcome, such as sinking in mud, jumping over logs, getting around rocks, or tangled up in bushes. In the end, the only robots that were capable of keeping up with him were so light and underpowered that he was able to tear them apart with his bare hands.

robot_muscleThis is a far cry from another science fiction staple, the one which presents robots as powerful automatons that can bend steel girders and carry out immense feats of strength. While some robots certainly can do this, they are extremely heavy and use hydraulics for the heavy lifting. Pound for pound, they’re actually very weak compared to a human, being capable of lifting only half their weight.

Another problem is the fact that robots using gears and motors, pneumatics, or hydraulics lack fine control. They tend to move in jerky motions and have to pause between each move, giving rise to a form of motion that we like to call “the robot”. Basically, it is very difficult to make a robot that is capable of delicate, smooth movements, the kind humans and animals take for granted.

kenshiroFor some time now, scientists and researchers have been looking to biomimetics to achieve the long sought-after dream of smaller, stronger robots that are capable of more refined movements. And taken in tandem with other development – such as the Kenshiro robot developed by roboticists at the University of Tokyo – that time might finally be here.

Developed by a four-person team led by Dr. Adrian Koh – from the NUS Engineering Science Program and Department of Civil and Environmental Engineering – the new artificial muscle is an example of an electroactive polymer. Basically, this is a combination dielectric elastomer and rubber that changes shape when stimulated by an electric field. In this respect, the artificial muscle is much like an organic one, using electrical stimulus to trigger movement.

 

robot-arm-wrestling-03-20-09Robots using artificial muscles would be a far cry from clanking mechanical men. They would be much more lifelike, capable of facial expression and precise, graceful movements. They would also have superhuman strength, yet weigh the same as a person. In addition, the polymer used to fabricate the muscles may have more general applications in machines, such as cranes.

An added bonus of the polymer is that is can convert and store energy, which means it’s possible to design robots that power themselves after charging for only minutes. In a statement released by his department, Dr. Koh highlighted the benefits of the design and what it is capable of doing:

Our novel muscles are not just strong and responsive. Their movements produce a by-product – energy. As the muscles contract and expand, they are capable of converting mechanical energy into electrical energy. Due to the nature of this material, it is capable of packing a large amount of energy in a small package. We calculated that if one were to build an electrical generator from these soft materials, a 10 kg (22 lb) system is capable of producing the same amount of energy of a one-ton electrical turbine.

AI_robotDr. Koh also indicated that robots equipped with these types of muscles “will be able to function in a more human-like manner – and outperform humans in strength.” Theoretically, such polymer-based tissues could extend to ten times their original length and lift up to 500 times its own weight, though the current version isn’t anywhere near that limit just yet.

In the meantime, Dr Koh and his team have applied for a patent for the artificial muscle and are continuing work on it. They predict that within five years they could have a robot arm that is half the size and weight of a human arm, yet could win an arm wrestling match. And the applications are limitless, ranging from robotic servants to search and rescue bots and heavy robot laborers. And let’s not forget that cybernetic arms that boast that kind of increased strength are also likely to become a popular prosthetic and enhancement item.

And for those who are naturally afraid of a future where super-human robots that have the strength to tear us limb from limb are walking among us, let me remind you that we still have Asimov’s “Three Laws of Robotics” to fall back on. Never mind what happened in the terrible movie adaptation, those laws are incontrovertible and will work… I hope!

Sources: gizmag.com, engadget.com, 33rdsqaure.com