AIP Publishing LLC
AIP Publishing LLC
  • Scitation
  • AIP
  • AIP China
  • University Science Books
  • Resources
    • Researchers
    • Librarians
    • Publishing Partners
    • Commercial Partners
  • Publications

    Find the Right Journal

    Explore the AIP Publishing collection by title, topic, impact, citations, and more.
    Browse Journals

    Latest Content

    Read about the newest discoveries and developments in the physical sciences.
    See What's New

    Publications

    • Journals
    • Books
    • Physics Today
    • Conference Proceedings
    • Databases
    • Scilight
    • Find the Right Journal
    • Latest Content
  • About
    • About Us
    • News and Announcements
    • Diversity, Equity, and Inclusion
    • Careers
    • Events
    • Leadership
    • Contact
  • Scitation
  • AIP
  • AIP China
  • University Science Books

Harvesting Energy from the Human Knee

  • July 17, 2019
  • Applied Physics Letters
  • News
Share:

Link to article: Macro fiber composite-based energy harvester for human knee
DOI: 10.1063/1.5098962

WASHINGTON, D.C., July 17, 2019 — Imagine powering your devices by walking. With technology recently developed by a group of researchers at the Chinese University of Hong Kong, that possibility might not be far out of reach.

The group describes the technology in Applied Physics Letters, from AIP Publishing. An energy harvester is attached to the wearer’s knee and can generate 1.6 microwatts of power while the wearer walks without any increase in effort. The energy is enough to power small electronics like health monitoring equipment and GPS devices.

Diagram of the slider-crank mechanism that generates energy during the knee’s motion. CREDIT: Gao et al.
Diagram of the slider-crank mechanism that generates energy during the knee’s motion. CREDIT: Gao et al.

“Self-powered GPS devices will attract the attention of climbers and mountaineers,” said author Wei-Hsin Liao, professor in the department of mechanical and automation engineering.

The researchers used a special smart macrofiber material, which generates energy from any sort of bending it experiences, to create a slider-crank mechanism — similar to what drives a motor. The authors chose to attach the device to the knee due to the knee joint’s large range of motion, compared to most other human joints.

“These harvesters can harvest energy directly from large deformations,” Liao said.

Due to the continuous back-and-forth the material will encounter when the wearer walks, every time the knee flexes, the device bends and generates electricity. This means the harvester can “capture biomechanical energy through the natural motion of the human knee,” according to Liao.

Previous wearable energy harvesters took advantage of the vibration caused in the device as a result of motion, which comes with drawbacks regarding efficiency.

“The frequency of human walking is quite slow, which significantly decreases the energy-harvesting capability,” Liao said. Because the group’s device uses a different method, it bypasses this limitation.

The prototype weighs only 307 grams (0.68 pounds) and was tested on human subjects walking at speeds from 2 to 6.5 kilometers per hour (about 1 to 4 miles per hour). The researchers compared the wearers’ breathing patterns with and without the device and determined that the energy required to walk was unchanged, meaning that the device is generating power at no cost to the human.

The researchers note the advantages of an efficient, wearable energy harvester and look towards future commercialization of the technology.

“Self-powered equipment can enable users to get rid of the inconvenient daily charge,” Liao said. “This energy harvester would promote the development of self-powered wearable devices.”

###

For more information:
Larry Frum
media@aip.org
301-209-3090

Article Title

Macro fiber composite-based energy harvester for human knee

Authors

Fei Gao, Gaoyu Liu, Brendon Lik Hang Chung, Hugo H. Chan and Wei-Hsin Liao

Author Affiliations

Chinese University of Hong Kong


Applied Physics Letters

Applied Physics Letters features concise, rapid reports on significant new findings in applied physics. The journal covers new experimental and theoretical research on applications of physics phenomena related to all branches of science, engineering, and modern technology.
Share:
  • Chaos Theory Produces Map for Predicting the Paths of Particles Emitted Into the Atmosphere
  • Finding Alternatives to Diamonds for Drilling

Keep Up With AIP Publishing

Sign up for the AIP newsletter to receive the latest news and information from AIP Publishing.
Sign Up

AIP PUBLISHING

1305 Walt Whitman Road,
Suite 110
Melville, NY 11747
(516) 576-2200

Resources

  • Researchers
  • Librarians
  • Publishing Partners
  • Commercial Partners

About

  • About Us
  • Careers
  • Events
  • Leadership

Support

  • Contact Us
  • Terms Of Use
  • Privacy Policy

© 2023 AIP Publishing LLC