A group of researchers at the University of Texas have made a breakthrough in their quest to find a stronger, more effective material for use in making artificial muscles for robots. They’ve found a way to create tangled nanotube ribbons that are, relative to weight, stronger than steel and stiffer than diamond.
The ribbons have the remarkable ability to expand in width by 220% when a voltage is applied. When the voltage is removed, the ribbons return to their normal state. The shift in state occurs over mere milliseconds. Additionally, the nanotube ribbons retain their properties in an extreme range of temperature: between -196 °C and 1538 °C.
The scientists construct the nanotube ribbons into an aerogel, which contains primarily air. A cubic centimeter of the stuff weighs just 1.5 milligrams; one gram could cover a space of 30 square meters. Researchers are still experimenting with ribbon lengths. So far, the team has produced ribbons that are 1/50th of a millimeter thick, 16 centimeters wide and several meters long. Larger sheets are in the works.
Besides serving as material for artificial muscles, the nanotube ribbons could be used to create sturdy, lightweight structures in space.
IF ROBOTS are ever going to be welcome in the home they will need to become a lot quieter. Building them with artificial muscles that run on hydrogen, instead of noisy compressed-air pumps or electric motors, could be the answer.
Kwang Kim, a materials engineer at the University of Nevada in Reno, came up with the idea after realising that hydrogen can be supplied silently by metal hydride compounds.
Metal hydrides can undergo a process called reversible chemisorption, allowing them to store and release extra hydrogen held by weak chemical bonds. It's this property that has led to the motor industry investigating metal hydrides as hydrogen "tanks" for fuel cells.
To make a silent artificial muscle, Kim and his colleague Alexandra Vanderhoff first compressed a copper and nickel-based metal hydride powder into peanut-sized pellets. They then secured them in a reactor vessel and pumped in hydrogen to "charge" the pellets with the gas. A heater coil surrounded the vessel, as heat breaks the weak chemical bonds and releases the stored hydrogen.
The next step was to connect the vessel to an off-the-shelf artificial muscle, which comprises an inflatable rubber tube surrounded by Kevlar fibre braiding. Two of these placed either side of a robotic joint can mimic the push/pull action of muscles by being alternately inflated and deflated (see diagram).
Turning the heater on and off controls the flow of hydrogen into the rubber tube, causing the muscle to move silently. Even better, the pair say, the muscle performs as well as those that run on compressed air systems (Smart Materials and Structures, DOI: 10.1088/0964-1726/18/12/125014). Importantly, the gas didn't leak.
"The system has biological muscle-like properties for humanoid robots that need high power, large limb strokes - and no noise," says Kim.
Yoseph Bar-Cohen, an engineer specialising in artificial muscle technology at NASA's Jet Propulsion Lab in Pasadena, California, says this is "a novel approach" for controlling artificial muscles. "It is an important contribution and increases the arsenal of potential actuators that may become available in the future," he says.
iRobot's latest robot is unique on many levels. The doughy blob moves by inflating and deflating - a new technique its developers call "jamming."
As the researchers explain in the video below, the jamming mechanism enables the robot to transition from a liquid-like to a solid-like state.
Earlier this week, researchers from iRobot and the University of Chicago presented the new "blob bot" at the IEEE/RSJ International Conference on Intelligent Robots and Systems.
As a new kind of chemical robot (or chembot), the blob bot has stretchy silicone skin, which is composed of multiple cellular compartments that each contain a "jammable slurry."
When some of these cells are unjammed, and an actuator in the center of the robot is inflated, the robot inflates in the areas of the unjammed cells. By controlling which cells are unjammed, the researchers can change the shape of the robot and make it roll in a specific direction.
The new robot is being funded by DARPA, which gave iRobot $3.3 million to work on the chembot last year. The goal is to build a robot that can squeeze through tiny openings smaller than its own dimensions, which could be valuable in a variety of missions.
The video shows the robot from about one year ago, and since then the researchers have been working on adding sensors and connecting multiple blob bots together.
Fair visitors look at the humanoid robotic system "Rollin' Justin" preparing a tea on March 2, 2009 at the world's biggest high-tech fair CeBIT in Hanover, central Germany.
Twendy-One demonstrates its ability to hold delicate objects by manipulating a drinking straw between its fingers at the Department of Mechanical Engineering laboratory in Waseda University in Tokyo, Japan, Wednesday, Jan. 14, 2009. The sophisticated robot has been developed by the university's team, led by Dr. Shigeki Sugano, in hope of supporting people in aging societies.
THE UBot whizzes around a carpeted conference room on its Segway-like wheels, holding aloft a yellow balloon. It hands the balloon to a three-fingered robotic arm named WAM, which gingerly accepts the gift.
Cameras click. "It blows my mind to see robots collaborating like this," says William Townsend, CEO of Barrett Technology, which developed WAM.
The robots were just two of the multitude on display last month at the International Joint Conference on Artificial Intelligence (IJCAI) in Pasadena, California. But this happy meeting of robotic beings hides a serious problem: while the robots might be collaborating, those making them are not. Each robot is individually manufactured to meet a specific need and more than likely built in isolation.
This sorry state of affairs is set to change. Roboticists have begun to think about what robots have in common and what aspects of their construction can be standardised, hopefully resulting in a basic operating system everyone can use. This would let roboticists focus their attention on taking the technology forward.
One of the main sticking points is that robots are typically quite unlike one another. "It's easier to build everything from the ground up right now because each team's requirements are so different," says Anne-Marie Bourcier of Aldebaran Robotics in Paris, France, which makes a half-metre-tall humanoid called Nao (pictured).
Some robots, like Nao, are almost autonomous. Others, like the UBot, are semi-autonomous, meaning they perform some acts, such as balancing, on their own, while other tasks, like steering, are left to a human operator.
Also, every research robot is designed for a specific objective. The UBot's key ability is that it can balance itself, even when bumped - crucial if robots are to one day work alongside clumsy human beings. The Nao, on the other hand, can walk and even perform a kung-fu routine, as long as it is on a flat, smooth surface. But it can't balance itself as robustly as the UBot and won't easily be able to learn how.
On top of all this, each robot has its own unique hardware and software, so capabilities like balance implemented on one robot cannot easily be transferred to others.
Bourcier sees this changing if robotics advances in a manner similar to personal computing. For computers, the widespread adoption of Microsoft's Disk Operating System (DOS), and later Windows, allowed programmers without detailed knowledge of the underlying hardware and file systems to build new applications and build on the work of others.
Programmers could build new applications without detailed knowledge of the underlying hardware
Bringing robotics to this point won't be easy, though. "Robotics is at the stage where personal computing was about 30 years ago," says Chad Jenkins of Brown University in Providence, Rhode Island. Like the home-brew computers of the late 70s and early 80s, robots used for research today often have a unique operating system (OS). "But at some point we have to come together to use the same resources," says Jenkins.
This desire has its roots in frustration, says Brian Gerkey of the robotics research firm Willow Garage in Menlo Park, California. "People reinvent the wheel over and over and over, doing things that are not at all central to what they're trying to do."
For example, if someone is studying object recognition, they want to design better object-recognition algorithms, not write code to control the robot's wheels. "You know that those things have been done before, probably better," says Gerkey. But without a common OS, sharing code is nearly impossible.
The challenge of building a robot OS for widespread adoption is greater than that for computers. "The problems that a computer solves are fairly well defined. There is a very clear mathematical notion of computation," says Gerkey. "There's not the same kind of clear abstraction about interacting with the physical world."
Nevertheless, roboticists are starting to make some headway.The Robot Operating System or ROS is an open-source set of programs meant to serve as a common platform for a wide range of robotics research. It is being developed and used by teams at Stanford University in California, the Massachusetts Institute of Technology and the Technical University of Munich, Germany, among others.
ROS has software commands that, for instance, provide ways of controlling a robot's navigation, and its arms, grippers and sensors, without needing details of how the hardware functions. The system also includes high-level commands for actions like image recognition and even opening doors. When ROS boots up on a robot's computer, it asks for a description of the robot that includes things like the length of its arm segments and how the joints rotate. It then makes this information available to the higher-level algorithms.
A standard OS would also help researchers focus on a key aspect that so far has been lacking in robotics: reproducibility.
Often, if a team invents, say, a better navigation system, they will publish the results but not the software code. Not only are others unable to build on this discovery, they cannot independently verify the result. "It's useful to have people in a sense constrained by a common platform," says Giorgio Metta, a robotics researcher at the Italian Insitute of Technology in Genoa. "They [will be] forced to do things that work, because somebody else can check. I think this is important, to make it a bit more scientifically oriented."
ROS is not the only robotic operating system vying to be the standard. Microsoft, for example, is trying to create a "Windows for robots" with its Robotics Developer Studio, a product that has been available since 2007.
Gerkey hopes to one day see a robot "app store" where a person could download a program for their robot and have it work as easily as an iPhone app. "That will mean that we have solved a lot of difficult problems," he says.
I like robots as much as the next geek and when they have web cams built-in that will allow me to see what’s going on in another room without having to get off my lazy duff I am all the more interested. The Rovio robot webcam is just such a device and I really want one.
If you already have your Rovio, you can now control the robot and see the live webcam feed right from your Android mobile phone. The application that lets you control the bot is called AndRovio and it’s from developer Poignant Projects.
You have full control over Rovio using the app from direction to camera position and everything in between. The app allows full control anywhere there is an available Wi-Fi connection. You can even get warnings on screen if the IR obstacle detector spots anything in the way. You can also use a 3G connection or even EDGE, but you can expect degraded video. The app is available for 99 cents on the Android Market.
