[Rhodes22-list] Energy Problem Solved!

[Michael D. Weisner]

Brad,

Engineers have long agonized over problems such as this - nothing new under 
the sun.
http://gendertree.com/a_stress_analysis_of_a_strapless.htm

Many of us have been concerned with the ability of bras to protect the 
finish on our "girls" as well: http://www.carbras.com/

Mike
s/v Shanghai'd Summer ('81)
Nissequogue River, NY


From: "Brad Haslett" <flybrad at gmail.com>Sent: Tuesday, June 24, 2008 8:40 AM
You gotta love science!  Brad

 <http://ad.doubleclick.net/click%3Bh=v8/36e9/3/0/%2a/n%3B199220758%3B0-0%3B0%3B26064088%3B4307-300/250%3B26302808/26320662/1%3B%3B%7Eokv%3D%3Bdir%3Dnews%3Bdir%3Dprint%3Bad%3Dbb%3Bsz%3D300x250%3Bajax%3Dn%3Btile%3D1%3Bheavy%3Dn%3BpageId%3Dslate-toolbar%3Bpoe%3Dno%3Brs%3Dj10285%3B%7Eaopt%3D0/ff/2600a3/ff%3B%7Efdr%3D198298846%3B0-0%3B1%3B14058711%3B4307-300/250%3B26559203/26577060/1%3B%3B%7Eokv%3D%3Bdir%3Dnews%3Bdir%3Dprint%3Bad%3Dbb%3Bsz%3D300x250%3Bajax%3Dn%3Btile%3D1%3Bheavy%3Dn%3BpageId%3Dslate-toolbar%3Bpoe%3Dno%3Brs%3Dj10285%3B%7Eaopt%3D2/1/2600a3/1%3B%7Esscs%3D%3fhttp://www.vzw-whoweare.com/>[image: Slate Magazine]technologyVictoria's CircuitHarnessing the untapped power of breastmotion.ByAdrienne SoPosted Monday, June 23, 2008, at 4:10 PM ET------------------------------As a woman who loves sports, I've always found the concept of breastsbothersome. If all goes according to plan, they will fulfill their intendedfunction for about three of the 70 years that I have them. The rest of thetime, they alternate between getting in my way and embarrassing me. They area favorite target of Frisbees and soccer balls. Finding sports bras is achore. Shirts don't fit.And these are just the physical discomforts. I am still tortured by thememory of three cousins standing in a circle around me, at theimpressionable age of 10, mocking my early development and telling me that Iwas going to be the Asian Dolly Parton. Fortunately, that never happened,but the possibility haunted my late childhood.Then one day recently I had an idea. As I rode public transportation to theoffice, my messenger bag slung uncomfortably across my chest, I thought,"Why not put the girls to work?" Human-powered devices are showing upeverywhere, from Rotterdam's sustainable dancefloor<http://www.enviu.org/cm/cm_index_site.html>tohuman-powered<http://www.inhabitat.com/2007/03/08/human-powered-gyms-in-hong-kong/>gymsin Hong Kong. The time seemed perfect—perhaps even overdue!—for a brathat could harness the untapped power of breast motion.The idea of an ener
gy-generating bra isn't as crazy as it might sound. Acompany called Triumph International Japan recently unveiled a solar-poweredbra <http://www.foxnews.com/story/0,2933,355737,00.html> that supposedlywill generate enough energy to power an iPod. But I live in foggy SanFrancisco and prefer not to walk around in my underwear in public. Couldsomeone design an iPod-powering bra for me?I decided to run the question past some scientists. It turns out that thephysics of breast motion have been studied closely for the last two decadesby a gamut of researchers, most of them women. LaJean Lawson, a formerprofessor of exercise science at Oregon State University, has studied breastmotion since 1985 and now works as a consultant for companies like Nike todevelop better sports bra designs. Lawson was enthusiastic about my idea butwarned it would be tricky to pull off. You would need the right breast sizeand the right material, she explained, and the bra itself would have to becleverly designed. "It's just a matter of finding the sweet spot, betweenreducing motion to the point where it's comfortable but still allowingenough motion to power your iPod," she said.Lawson explained that breasts move on three different axes: from side toside, front to back, and up and down. The most motion is generated on thevertical axis. Naturally, the bigger the breast, the more momentum itgenerates. "Let's face it—if you're a double-A marathoner, you're probablynot going to get that iPod up and running," Lawson said. Measurementscompiled by Lawson and her colleagues show that a D-cup in a low-support bracan travel as much as 35 inches up and down (35 inches!) during exercise,while a B-cup in a high-support bra barely moves an inch.Fabric and design are also important factors in distance traveled. Elasticfabric allows the breast to move more. Choosing between an encapsulationdesign, in which the cups are separated, or a compression design, where theyare hugged close to the body, can also affect breast motion. Anencapsulation design further reduc
es motion because two smaller masses areeasier to control than one large one. "Also, if you have a really highneckline, the breasts won't fly up," Lawson said. So I was in the market foran elastic, compression-style bra with a low neckline. Sexy!Of course, even a bra that perfectly maximized motion (without sacrificingsupport and comfort) would be useful to me only if there were a way to turnthat motion into energy. For a primer on how to do that, I turned toProfessor Zhong Lin Wang of Georgia Tech, who is currently working todevelop fabric made from nanowires that will capture energy from motion.Wang's wires are about 1/1,000th the width of a human hair. When woventogether in a fabric, these nanowires rub up against one another and convertthe mechanical energy from the friction into an electric charge. Accordingto Wang, the fabric is cheap to produce and surprisingly efficient; his teamhopes to use it to create energy-generating T-shirts and other articles ofclothing. A square meter of fiber produces about 80 milliwatts of power,which is enough to run a small device like a cell phone. Wang expects tohave a shirt available for purchase within five years.Many bra patterns call for about a meter of fabric, which would probablymean that a regular bra would have enough energy to power an iPod. But thefabric could also be layered, doubling or even tripling the amount of energyproduced. I asked Wang whether his fabric could be used to make a bra. "Braswould be ideal," he said. "There is a lot of friction and movement in thatgeneral area. And the fabric would be thick.""So you can generate enough energy to power an iPod?" I asked."Definitely," Wang said.I asked Wang if this bra would be machine-washable."You don't need to wash a bra!" he said.I disagreed. Wang said his team has been working on the washing problem fora while. Nanowire technology can generate electricity only if the spacebetween the wires is maintained, and that space might be affected if thefabric were agitated by washing. One solution would be to layer
 the fabricso that the parts that directly touch the skin could be washed, leaving thenanowires in between untouched.There was one more approach I wanted to investigate, one that mightsupplement Wang's technology. Was there a way to capture the energy of thebra strap, which bears the pressure of holding up the breast mass? To answerthis question, I called Larry Rome, a biology professor at the University ofPennsylvania and the creator of LightningPacks<http://www.usatoday.com/tech/products/gear/2005-09-08-electric-backpack_x.htm>.The Lightning Pack, intended for long-haul hikers and for the military,generates kinetic energy from the vertical displacement of a heavy backpack.Would it be possible to use the kinetic energy generated from a breast'svertical displacement?"The backpacks we've built are intended to carry between 40 to 80 pounds,"Rome said.I cited the D-cup numbers given to me by Lawson. "Well, that's not normal,is it?" Rome asked.I said that it probably wasn't. Yet after a moment's thought, Rome came upwith an idea. The Lightning Pack uses a rotary generator, which convertsmotion into energy by winding a rotor as the backpack moves up and down.Rotary generators produce up to 7 watts of energy, enough to power a compactfluorescent light bulb. Rome said it might be possible to insert a lineargenerator into the bra. A linear generator is a lot smaller and createsenergy by moving a piston up and down. Rome conceded that with the rightbody type, this just might work, though he warned it "probably wouldn't bevery comfortable."Still, if someone were to engineer a kinetically powered bra, even one thatisn't quite as comfortable as the old-fashioned kind, I'd be intrigued—and Imight just start looking at my breasts in a different light. Maybe it's notvery sexy to see breasts as a pair of batteries, but oil prices are so high,people are jogging to work. It may be time for breasts to start pullingtheir own weight.*Adrienne So is a researcher and writer for *Wired *magazine. **Article URL: http://www.slate.com/id/
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