Shapeshifters: The Coming Age of Smart Materials

Stephen DeAngelis

June 17, 2011

You might be asking yourself what a post about shapeshifting materials has to do with the business topics about which I normally write. If you watch the videos I’ve included in this post, you’ll understand that so-called “smart materials” could potentially impact any number of business sectors, including manufacturing, transportation, and the supply chain. Shapeshifters (be they machines or creatures) have been a staple of science fiction for decades (if not centuries — think about Dracula and werewolves). We’re probably not going to be seeing any X-Men-like human shapeshifters anytime soon, but materials are being discovered and created that are eerily similar to computer-generated imagery (CGI) found in movies like The Terminator. The following video provides a good introduction to the subject.

 

 

If you didn’t have time to watch the video, it talked about non-Newtonian fluids. The classic non-Newtonian fluid is created by mixing water and corn starch. Wild and crazy, fun-loving scientists have for years gotten chuckles by filling tubs with the stuff and running across it. Hit the mixture with a fast blow, like running feet, and it stiffens into a semi-solid state — stop running and you sink into the mixture in its liquid form. The video also discusses magneto rheological (MR) fluid which changes from a liquid to a semi-solid state when exposed to a magnetic-field. Interesting stuff. In other research, a German materials scientist, Dr. Jörg Weißmüller, and a Chinese research scientist, Hai-Jun Jin, “have created a metallic material that can change back and forth between being strong but brittle and soft but malleable, via electrical signals.” [“Metallic material can switch back and forth between hard and soft states,” by Ben Coxworth, Gizmag, 7 June 2011] Coxworth reports:

“The metals used in the material are typically precious ones, such as gold or platinum. They are placed in an acidic solution, which causes minute pores to form within them – in other words, they start corroding. Those pores are then impregnated with a conductive liquid, such as saline solution or diluted acid. By varying an electrical current that is applied to the liquid, electrons are added to or withdrawn from the surface atoms of the metal. This can increase the strength of the material as a whole by up to 200 percent, or it can cause it to become softer, but also better able to absorb energy without shattering.”

Sounds like a very expensive experiment. Like me you might be wondering what practical applications this breakthrough might have. Coxworth explains:

“Not only could the strength of an entire component made with the material be controlled with the flip of a switch, but it is also conceivable that the material could create its own electrical signals within specific regions, in response to mechanical stress. In this way, it could mostly remain strong and hard, yet selectively allow parts of itself to become malleable in order to avoid cracking. Existing cracks could perhaps also be healed. ‘For the first time we have succeeded in producing a material which, while in service, can switch back and forth between a state of strong and brittle behavior and one of soft and malleable,’ said Weißmüller. … ‘We are still at the fundamental research stage but our discovery may bring significant progress in the development of so-called smart materials.'”

Efforts to create smart materials include materials that can be programmed to change shape. These materials could be used for activities ranging “from tools that morph themselves structurally to suit the job at hand to sentry bots that can change shape to squeeze through narrow passageways.” [“DARPA’s “Programmable Matter” Project Creating Shape-Shifting Materials,” by Dan Smith, POPSCI, 8 June 2009] Smith reports:

‘”Programmable matter’ is such a far-out concept that it’s difficult to imagine it even existing outside the movies. But, thanks to some creative work done by scientists funded by DARPA (who else?), it might actually become a reality, creating materials that can be programmed to alter themselves at the molecular level into various shapes and then disassemble to form entirely new ones. Imagine universal tools that can morph to perform the specific job needed. Imagine vehicles and clothes that that can automatically change shape–perhaps even at the molecular level–according to terrain or climate.”

Smart material that is programmable at the molecular level may be a ways off — I just don’t know; but Smith also talks about at team at Harvard that “has created ‘self-folding origami,’ structures with integrated actuators and data storage that will fold themselves into different shapes.” Watch the following video to see how the material works.

 

 

Smith reports that others are also working on shapeshifting materials. He writes:

“A team from MIT has even built tiny servo motors that can control the assembly of objects underwater or in space. Other teams have approached [the] problem by mimicking DNA or [protein]-synthesis in the creation of objects. … Once some of these ideas are realized or integrated into a working form, the possibilities are almost endless. Blurring the line between materials and mechanics, it may even result in new states of matter. One possibility are ‘infoliquids’ and ‘infosolids’, materials [that] straddle the line between solid and liquid, with information encoded into its chemistry. Another possibility is the creation of robots that can shift sizes and even states of matter to squeeze through narrow passages or around obstacles. Wired also points to Intel, which has done research into the field as well, theorizing models that can mimic shapes in real-time, similar to holograms. This could allow a replica of yourself to exist and move as you do somewhere on the other side of the world. Forget Autobots and Decepticons, this is the real deal.”

Apparently CNN did a report on Intel’s research into claytronic atoms, or catoms, that included a video that Dan Gould called “absolutely mind blowing.” [“Ultimate 3D Printing: Intel’s Shape-Shifting, Programmable Matter,” psfk, 6 March 2009] The video was removed from YouTube because CNN asserted its copyright and I couldn’t find a link to the report. Writing about Intel’s work, Mark Hachman wrote, “Eventually, clothes or objects could be manipulated, so that their form and function could be shifted dynamically. Imagine a PDA that could transform itself into a marble or bracelet when not in use.” [“Shape-Shifting Materials, Wireless Power at IDF,” ExtremeTech, 21 August 2008]. Hachman explains what catoms are:

“Essentially, catoms are tiny silicon spheres or tubes, small enough that they could be manipulated by electrostatic or electromagnetic forces. The demonstration by Jason Campbell of Intel Research Pittsburgh showed an array of a few spheres just a few millimeters wide – smaller than a penny – where orientation could be slightly, slowly manipulated. Really cool to watch, but … The reality: This is far, far away. As Envisioneering analyst Peter Glaskowsky remarked, ‘On a scale of 1 to 100, where 100 is making catoms a reality, they’re at 0.1.’ Still, Intel has already shown that catoms can be manufactured with the same photolithography techniques they use to make chips.”

One of the things that Smith discussed above was “robots that can shift sizes and even states of matter to squeeze through narrow passages or around obstacles.” An article in The Economist talks about the usefulness of such robots. [“Return of the blob,” 8 March 2010] The article reports:

“Trapped under a pile of rubble, you wait for rescue. Then, to add to your troubles, you see a small blob ooze through a nearby crack. It is not, however, an extra from a horror film in search of a meal, for soon afterwards it is followed by the emergency services digging down to find you. This scene is science fiction now, but it might not be for much longer. Traditionally, people have thought of robots as whirring bits of metal, but there are those in the field who ask why that need be so. Instead of trying to build a robot that looks like a human, an insect or even a tank, some robotics experts have decided to look to the humble amoeba for inspiration.”

Once again it is DARPA that is behind the research to create these kinds of robots. The article reports that DARPA provided a research grant to “iRobot (a company best known for its vacuum-cleaning robot, the Roomba).” The goal that DARPA is aiming for is a robot that can “fit through an opening half its full diameter.” The article continues:

“The result is the blob-like Chembot, which moves by deforming one side. To achieve this, iRobot’s engineers used a concept called ‘jamming’, which takes advantage of the fact that some particulate materials are quite stiff when compressed but, given space, flow like liquids. Dr Jones says the phenomenon is much like that observed in a vacuum-packed coffee brick. An unopened brick is stiff and strong because the external air pressure is compressing it. When the plastic or foil is cut, however, air gets in, equalising the pressure. The coffee then acts like the pile of particles it is, and the brick can change shape. The Chembot is a vaguely spherical structure made of soft triangular panels, each of which is filled with particles. The control system, which uses tiny compressors to pump air in and out of the panels, is in the centre. The triangular panels remain stiff until a small amount of air is pushed inside them. That lets the particles move around and allows the panel to deform. Increasing the pressure inside one set of panels while holding it constant in the others causes the robot to bulge out on one side and thus move in the opposite direction. This deformability, however, permits more than just movement. It also allows the robot to enter any space no smaller than its fully compressed state, more or less regardless of the shape of that space.”

The Economist reports that iRobot isn’t the “only contender for the artificial-amoeba crown.” The article states that a mechanical engineer at Virginia Tech named Dennis Hong is also working on the problem, but using a different approach. It explains:

“He has looked at the way natural amoebas move, and tried to replicate it. The Chembot moves by pushing itself along. Real amoebas, however, pull themselves. They extend a pseudopod in the direction they wish to travel, and the rest of the amoeba then flows forward into the pseudopod. Dr Hong could not exactly duplicate that, but he came up with something similar: the idea of an extended toroid. The toroid would simply turn itself inside out, accomplishing by different means the same thing the amoeba does. For bigger robots, he accomplishes this with a series of hoses, arranged like ribs, to form the torus. Each hose can be expanded and contracted independently. Doing so in sequence along the length of the torus generates forward motion. For small robots Dr Hong has used rings made of a polymer that changes shape in response to a specific chemical stimulus. The result is a robot that scuttles along when an appropriate chemical is brushed on one end. Dr Hong will not yet say which chemicals he uses, but the robot moves impressively fast. It can also, like the Chembot, squeeze through openings smaller than its initial diameter.”

The article notes that such robots could be useful beyond the search and rescue scenario it proposed. For example, they could be used in “endoscopy—the process by which doctors insert a camera into someone through an orifice to perform an internal examination.” That doesn’t sound very pleasant; but, the article reminds us, “at the moment, the camera has to be fitted to the end of a stiff, yet flexible cable.” It concludes, “A soft, squishy robot, sufficiently small, could be an alternative. How patients would feel about having an autonomous blob roaming around inside them is another matter.”

 

Materials that can change in response to external conditions could prove very useful in the supply chain. It is not hard to imagine how reusable, programmable packaging material could help protect oddly-shaped or extremely fragile goods in transit. Until the materials become a reality and can be produced in large quantities, we won’t really know how creative people will put them to use. Smart materials is an exciting field and worth watching.