The product could also be used less gloriously under a floor pad in a shopping mall, such that pedestrians walking over it would power sales signs
PRINCETON BOROUGH — Chemist Michael McAlpine stands in a disorderly basement laboratory at Princeton University holding a small, gold-rimmed square of silicone imprinted with a bit of conductive material. The lab, the silicone, McAlpine himself, everything looks so random.
But this is science, and what looks like disorder to the rest of us is elegant in the eyes of the chemist, who has thought outside of the box just enough to execute a brilliant idea: Harvest the body’s untapped energy to power internal implants like pacemakers. And use this tiny piece of imprinted silicone to do it.
“I don’t really know how I thought of it,” said McAlpine, who is not kidding. “I just did.” It’s unlikely he will ever identify the precise eureka moment. But McAlpine, 32, an assistant professor in the Department of Mechanical and Aerospace Engineering at Princeton, has a serious résumé of early achievement behind him and a record of making connections where none obviously existed.
Somewhere in all of that lie the seeds of his invention. “You can call it piezo-rubber energy harvesting,” McAlpine says, brandishing the silicone.
To understand the technology, you need only recall from childhood how newspaper print can be imprinted on a piece of Silly Putty just by squashing the two items together.
With that kind of ease, scientists can imprint a piezoelectric material — that is, creating energy from pressure — onto a square of silicone. When the silicone is flexed or bent, the material layered on it, piezo, for short, releases a small burst of energy (having to do with positive and negative ions switching places upon compression). If implanted in a patient’s body, the simple act of breathing in and out — which is enough movement to flex the piezo — would generate wattage sufficient to power a pacemaker.
The need for painful and intrusive surgery to replace internal pacemaker batteries for these patients would be greatly reduced.
“The average human consumes or dissipates about 100 watts of power a day,” said McAlpine. “And about one percent of that is dissipated by your lungs, so that’s one watt. Most of your power is dissipated when you walk, that’s like 70 watts. But just breathing equals out to one watt. That’s a fair amount of power in your lungs.”
McAlpine has in mind that the piezo-silicone square would be affixed to the rib cage and attached with a small wire to the pacemaker. All the invention needs now — since it already has a patent and the endorsement of the university community — is a company to produce and manufacture it. If it flies, McAlpine figures it’s about five years from commercial use.
(The product could also be used less gloriously under a floor pad in a shopping mall, such that pedestrians walking over it would power sales signs.)
There are other projects as well. There is the test McAlpine invented to detect bacteria on pharmaceutical implants that uses peptides and synthetic materials as its basis, where pharmaceutical companies now use horseshoe crab blood, of all improbable things. That test is under patent as well, and will be introduced to the public in an article in the prestigious journal Proceedings of the National Academy of Sciences in the next couple of months.
This is McAlpine’s life: Hang around in his sparse office in Engineering Quad D, visit the laboratory, advise students, play the guitar in his apartment in Lawrence, think up brilliant ideas.
“Michael was an outstanding candidate for our department, and it’s still very early in his career. He is doing things that a lot of people have tried to do, putting these electronics on flexible sensors. But he’s doing it very creatively and in the context of these extraordinary applications,” said Professor Alexander Smits, chair of the department. “He just has a different way of thinking, and he sees these opportunities of using this technology that others haven’t seen. We saw something very unusual in him.”
McAlpine grew up in Fairfield, Conn., with a best friend whom he describes as “smarter than me.” (That friend now works at Microsoft.) The two of them were bused from their middle school to the high school for math classes, having placed way off the charts for the average eighth-grader. “It was really embarrassing,” McAlpine recalls. “It was just my friend and I and this one other kid on the bus.”
A few years later at Brown University, McAlpine had his first major success in a chemistry lab, discovering and then mapping out two new molecules. He describes the discovery as mostly lucky, having left his exertions with the molecules in frustration to go home for a week of vacation. He returned to a congealed, crystallized set of molecules whose structure was quite clear.
“I was pretty excited, yes. But that’s the thing about science. There is a lot of serendipity,” said McAlpine. “So 95 percent of your time is failure. You have to be able to put up with that. You have to be the type of person in which that 5 percent makes up for everything else, and not everyone can handle those kinds of massive highs and massive lows. I am definitely not a patient person, but I can handle that.”
In a move that would lay the foundations for his future projects, McAlpine went next to Harvard University, working with Chemistry Professor Charles Lieber to build a computer on a piece of plastic that you could roll up and carry under your arm. The effort remains just that, an ongoing effort. But it taught McAlpine a good deal about nanoelectronics and the value of applied science as opposed to pure research.
“I’m not really a basic science person. I like to do things that are applied, things that make sense in the real world. So I wanted to get away from just synthesis and do something more,” he explains. “I like the idea of using these materials to build things that have some meaning.
“Charlie Lieber is, like, the father of nanowire technology. We were trying to build computers onto plastic, pure electronics on plastic. It is a similar imprinting technique to this piezo. The whole thing about this piezo is that you bend it to produce the power. So it just made sense to me to apply it to the idea of pacemakers.
“But someone else could easily have come up with it.”
However that is the genesis of any really good idea — it seems simple and obvious only after someone else has already thought it up. McAlpine has lots of ideas and wants merely a bit of open space in which to create, a fact that has its physical expression in his office. There is hardly anything in it. Few books. Very little on the walls. A visitor inquired if this was a new office for McAlpine; perhaps he had not moved in yet.
“No. I like it like this. My apartment looks the same. Mostly I just don’t like stuff getting in my way. I like to move freely about without clutter and have not only that but wide-open opportunities,” he said.
An undergrad degree from Brown; graduate work at Harvard; more graduate work at the California Institute of Technology; a departmental position at Princeton, where he has already provided ample evidence of an agile brain — all within his 32 years on the planet.
“Wide-open” is indeed one of the phrases that springs to mind.
Source: http://www.nj.com/mercer/index.ssf/2010/09/princeton_chemist_finds_way_to.html
