Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

Rewriting Life

Power Walking

Taking a vigorous walk tones the muscles; soon it could recharge your personal electronics too. Researchers at SRI International say they’ve built a boot that can convert 2.5 hours of walking into enough electricity to provide 20 minutes of cell-phone use. The key ingredient is a polymer that generates electricity when flexed. It’s one of the so-called dielectric elastomers, which are more rubbery, flex farther and produce much more power than the piezoelectric materials used in earlier attempts at power-generating shoes, says Ronald Pelrine, who heads the SRI project. The U.S. Defense Advanced Research Projects Agency, which is funding SRI’s research, is seeking boots that can power electronics like navigation aids. The polymer could also ease the strain of marching by expanding quickly after each step, giving the foot a small boost, Pelrine says. But any shoe-mounted generator has its power limits, he says, beyond which the shoe would become uncomfortable-“like walking in mud.”

More from Rewriting Life

Reprogramming our bodies to make us healthier.

Want more award-winning journalism? Subscribe and become an Insider.
  • Insider Plus {! insider.prices.plus !}* Best Value

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus the digital magazine, extensive archive, ad-free web experience, and discounts to partner offerings and MIT Technology Review events.

    See details+

    Print + Digital Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

    Technology Review PDF magazine archive, including articles, images, and covers dating back to 1899

    10% Discount to MIT Technology Review events and MIT Press

    Ad-free website experience

  • Insider Basic {! insider.prices.basic !}*

    {! insider.display.menuOptionsLabel !}

    Six issues of our award winning print magazine, unlimited online access plus The Download with the top tech stories delivered daily to your inbox.

    See details+

    Print Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

  • Insider Online Only {! insider.prices.online !}*

    {! insider.display.menuOptionsLabel !}

    Unlimited online access including articles and video, plus The Download with the top tech stories delivered daily to your inbox.

    See details+

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

/3
You've read of three free articles this month. for unlimited online access. You've read of three free articles this month. for unlimited online access. This is your last free article this month. for unlimited online access. You've read all your free articles this month. for unlimited online access. You've read of three free articles this month. for more, or for unlimited online access. for two more free articles, or for unlimited online access.