U of U researchers are working to bring cloaking devices and more to the real world.
By John Blodgett
Human ingenuity eventually seems to catch up with the most far-out ideas ever concocted in comic books, in science fiction action films, and in the minds of the likes of Leonardo da Vinci. Sometimes it just takes a while—a long while, in many cases—for the formerly make-believe to make believers out of skeptics. The following three projects at the University of Utah aren’t necessarily anywhere near the last stage of development, yet each has already pushed one boundary after another.
Building body parts that build themselves
Glenn Prestwich, presidential professor of medicinal chemistry
The challenges of transplanting organs and tissues are well known. First is the difficulty of finding a donor. Second is the matter of compatibility between one person’s tissue and another’s—a heart, liver, kidney, or skin can easily be rejected by the recipient’s body.
Growing an organ outside the body, using the patient’s own tissue, could solve both problems. And a University of Utah faculty member is helping to make that happen.
Over the past 12 years, Glenn Prestwich, presidential professor of medicinal chemistry at the U, has developed what he calls “synthetic extra-cellular matrix (ECM) technology.” “The ECM is what surrounds all of your cells,” he explains. “A large portion of our bodies is made of these matrixes.” His goal and that of other “tissue engineers” is to use a synthetic equivalent of the ECM, which could then be added to cells to rework the ECM into whatever form necessary—such as a heart or a liver.
Prestwich says the ECM can be thought of as a framework in which cells grow, proliferate, and differentiate in three dimensions. The tendency of many past researchers, however, has been to consider such a framework a temporary structure, a scaffold erected to ease the construction of cellular material and then dismantled when done. The problem with this way of thinking and with previous technology, says Prestwich, is that the ECM could actually become an obstacle to tissue regeneration.
That’s not the case with Prestwich’s tissue engineering work, in which he compares the support structure to the frame of a house. His approach has been to focus on developing a technology that is more “organic” to allow cells to remodel the framework into a natural, integral ECM.
The ECM technology Prestwich and his team have developed over these past 12 years has enabled the organic growth of something else—namely, three companies (thus far) that commercialize the fruits of their labors. Funding from one of the state’s Centers of Excellence and other programs has helped to grow these ventures, all of which are proving successful.
One of these companies, Sentrx Animal Care, is developing technology to assist veterinarians in healing wounds and repairing tissue. The ECM technology has been used to treat “everything from dogs and cats to horses, to penguins with what’s called ‘bumble foot,’ to hawks that have had damaged wings,” says Prestwich.
Other applications of the technology being developed by Glycosan BioSystems, another company Prestwich founded, include drug evaluation, in which organ tissue can be grown ex vivo for the purpose of testing. It’s a replication, not a simulation, of human cells, so testing is effectively carried out in real-world conditions. Prestwich says it’s “like having 96 livers in something the size of an index card.”
Because the originating cells for this testing come from a real person, it becomes possible to tailor diagnosis and treatment to the individual. If, for example, a person has a tumor of some sort, ECM technology allows cells to be extracted from that tumor, assembled with the ECM, and injected into mice for “humanized” testing, explains Prestwich. The purpose is to reduce the guesswork in selecting an experimental therapy for patients with multi-drug-resistant cancers.
“The key is to avoid trying to play divine engineer [and instead] engineer what we want cells to do,” says Prestwich. “There used to be a mentality that we had to build it perfectly and put it in,” he explains. Now the scientific community is realizing the need to encourage the actual biological processes, allowing Mother Nature to take the lead.
Fortunately, the evolution of the biotechnology has evolved in such a way as to allow tissue to regenerate itself. “We let the biology do all the heavy lifting,” says Prestwich.
A robot that you wear
Raytheon Company test engineer Rex Jameson demonstrates the "real" Iron Man exoskeleton suit.
The recent movie Iron Man offers a glimpse of what the Raytheon Company and U of U researchers have in the works—a kind of “wearable robot” that allows a user to repeatedly lift up to 200 pounds, punch a speed bag, and run up stairs, all without tiring.
Raytheon public relations has played up the semblance between the character in Iron Man and the exoskeleton suit. The former debuted on May 2, 2008; the latter was featured in that month’s issue of Popular Science, which reported that Raytheon had the “real” Iron Man, a claim the company echoed in a press release near the movie’s launch, touting: “Raytheon is pushing the boundaries of technology to where science fiction will one day meet reality.”
Stephen Jacobsen BS’67 MS’70, University of Utah Distinguished Professor of mechanical engineering, who leads the Raytheon Sarcos team in Salt Lake City, has described the exoskeleton not as a product of a “mad scientist” but rather the result of a “process of getting together, understanding the problems [and] goals, and then designing something to satisfy the need.” To him, it’s a blend of art, science, engineering, and design.
The press jumped on the story. Newspapers the world over reported on Jacobsen’s creation—so much so that he and test engineer Rex Jameson MS’95 eventually withdrew from the flurry of media attention. (Neither would respond to multiple requests for interviews for this article.)
Even in still photographs, the exoskeleton looks like it’s in motion; the effect is heightened when Jameson isn’t wearing it. It seems to have jumped right out of CGI (computer-generated imagery) animation. Jameson steps into what appear to be Teva sandals made for lunar exploration and straps on the exoskeleton. The suit looks a bit awkward, but that’s belied by the degree to which it can predict, mimic, and magnify human motion. The suit appears tough and delicate all at once.
The present exoskeleton is the third prototype built since the idea was conceived in 2000. It currently is under development for the United States Army as part of a two-year, $10-million contract—the only full exoskeleton the military has moved into the next development stage, reports Australia’s Daily Telegraph.
It’s apparent that the Raytheon Sarcos guys are having fun, and not just with the movie connection. Jameson, the man who suits up in the exoskeleton for media demonstrations, said in the same Daily Telegraph article that “as far as software engineering goes, this job is about as good as it gets.”
The cloak of invisibility
Distinguished Professor Graeme Milton explains how cloaking could work.
Now you see it, now you don’t. Invisibility at will has long been part of the world of superheroes, but now, with the advent of the superlens, the cloak of invisibility is jumping from the pages of comic books to the real world. Graeme Milton, Distinguished Professor of mathematics at the U, is beginning to see his work on cloaking come to light.
It might seem unusual for a mathematician to get involved with invisibility, but Milton points out that applied mathematics is, in actuality, a broad discipline that encompasses biology, engineering, physics, and other areas of study. With a background in physics, Milton says it was “natural” for him to become involved in this kind of work, which he and his colleagues Nicolae Nicorovici and Ross McPhedran, at the University of Sydney in Australia, began in 1994.
It’s difficult to state their work in terms other than how Milton describes it. While researching properties of arrays of composite materials that contained coated cylinders, they discovered some fascinating properties: When the shell coating a single cylinder had negative properties, that cylinder would act like a solid cylinder of much larger radius. “The shell, in effect, acted like a magnifying glass,” explains Milton. “That’s where our research started, and we should have followed it up further at the time but didn’t realize the importance of the result.”
Milton’s interest in the problem rekindled in 2000 when Sir John Pendry, a solid state physics theorist at Imperial College London, obtained a closely related result and found himself awash in the scientific spotlight. He discovered that a slab of material with negative electrical and magnetic properties acted like a lens—not a normal lens but one unimpeded by diffraction.
This lens was christened a “superlens,” and Milton explains one potential application of the discovery. “The reason microscopes can’t see atoms is because they are limited by diffraction. [The superlens] promises new types of microscopes that might see much more detailed information.” Essentially, Milton’s work in 1994 had identified the first cylindrical superlens.
Milton was on sabbatical in his native Australia when he came up with the notion of cloaking. It was in response to a comment by Alexei L. Efros, Distinguished Professor of physics at the U, who saw a potential paradox associated with the superlens: If you put a point source near the superlens, the math would suggest that the superlens would absorb an infinite amount of energy; but how could this be possible if the source were providing only a finite amount of energy? Milton and his collaborators found that cloaking was the answer to this paradox.
But where previous research posited that the cloaking region lies inside the cloaking device, Milton’s work suggests that it lies outside the device. “It’s a completely different mechanism for cloaking, one that even sci-fi writers haven’t thought about,” he says. “And the cloaking device in our case is a superlens” that isolates particles from their surroundings, creating a cancellation effect that makes them appear invisible from the outside.
The work still has a ways to go before it can be applied to real-world situations, whether to microscopes or something else. Milton even muses about related technology some day, long away, protecting a building from being destroyed in an earthquake.
“There are military [and other] applications that people wonder about,” Milton acknowledges. “But it’s hard to predict at this stage” what other kinds of uses visionary thinkers might yet devise.
—John Blodgett is a Salt Lake City-based freelance writer.
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