Piezoelectric Energy-Harvesting System That Can Generate Electricity From Vibration

Technology #13608

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Researchers
Toshikazu Nishida
David Bloomquist
Managed By
Richard Croley
Assistant Director 352-392-8929
Patent Protection
US Patent 9,431,929

Invention

The University of Florida is seeking companies interested in commercializing an energy-harvesting system that makes it practical to capture and store energy from piezoelectric transducers embedded in such practical sources as roads and flooring. These self-powered sensor nodes can harvest local energy. They are untethered from the wired power grid or require the use of batteries, which substantially increases the flexibility of their deployment. The sensor nodes can harvest mechanical energy in the form of vibration and strain in situations where solar optical energy is not dependable, i.e. cloud cover, and for embedded applications. Available mechanical energy harvesters such as those based on cantilevers can tap vibrational energy, but the energy decreases substantially if the vibration frequency does not closely match the resonant frequency of the cantilever. The unique system developed by University of Florida researchers operates asynchronously in a non-resonant manner, harvesting energy from external force impulses using a novel, low-profile mechanism that transfers fluidic force to a series of compliant piezoelectric layers.

Application

Asynchronous piezoelectric energy-harvesting system that uses fluidic force transfer to harvest energy from vibration in flooring, roadway striping, bridges and structures, and deformable objects such as golf balls, among other potential sources. The system can also be manufactured using standard micromachining techniques employed in microelectromechanical systems (MEMS).

Advantages

  • Does not require consistent or predictable vibrational frequency to produce energy, increasing potential usage and adoption rate
  • Takes advantage of various kinds of force or strain, allowing for a wide range of applications, including flooring, bridges, and roads
  • Can generate electricity from practical situations, widening the market
  • Increases the efficiency of energy harvesting, providing a competitive advantage

Technology

Of the various kinds of energy-harvesting technologies in use today, piezoelectric energy harvesting has the unique ability to generate electrical energy simply through the input of vibration or external force impulses. However, in certain applications, the vibrational frequency range required to generate consistent energy is a very limited. Because real-world situations typically have inconsistent or varying vibration frequencies, this requirement severely limits its practicality. University of Florida researchers have developed a system that not only removes this limitation but also increases the energy harvesting efficiency. The system employs a fluidic transfer mechanism where force, when exerted on the wear-resistant cover, is transferred into the fluid layer below and the encapsulated compliant piezoelectric membranes. The fluid can either be compressible, reducing the applied force, or non-compressible, maximizing the amount of force that is transferred to the piezoelectric membranes. The system is asynchronous, meaning that it does not require consistent or predictable force or vibrational frequency to function efficiently.