Energy harvester from University of Warwick can produce energy even at the lowest wind speeds.

Benefits

  • Resilient
  • Versatile
  • Efficient

Applications

  • Commercial and residential energy generation
  • Renewable energy

UN Sustainable Development Goals Addressed

  • Goal 7: Affordable & Clean Energy

The Challenge

Machines used for energy generation often require many moving parts that enable the machinery to operate. These parts are connected with bearings, connection pieces that allow rotation and movement. Unfortunately, these pieces do not work as well in environments with extreme cold, heat, dust or sand, limiting the situations in which they are operational.

Innovation Details

The energy harvester is designed to mimic how Aspen leaves tremble in even the slightest breeze. The researchers created a mathematical model that mimics this movement. They then used a low speed wind tunnel to test a device with a cantilever beam similar to the flat stem of the Aspen leaf. It also has a curved blade tip with a circular arc cross section that functions as the main leaf. The blade was oriented perpendicular to the flow direction, allowing the harvester to produce self-sustained oscillations at extremely low wind speeds, similar to the aspen leaf. In addition, the energy harvester can generate power without the use of bearings. Although the power generated is small, it is sufficient to power autonomous electrical devices. These are often used in applications such as automated weather sensing in remote and extreme environments.

Biomimicry Story

The leaves of the Aspen tree quake when the slightest breeze passes by due to the structure and connection of the stem. Unlike typical plant stems, the aspen tree has a flat petiole. The petiole is the stalk where the leaf blade attaches to the stem. Because the petiole is flat, it acts like a pivot for the leaf to move on, and allows it to move in even the slightest breeze.