FLEXIABLE AND TUNABLE ACOUSTIC TRANSDUCERS FOR ENERGY HARVESTING
Abstract
The objective of this study is to explore a novel energy harvesting systems based on superior piezoelectric properties of two independent systems, 1) piezoactive fibers produced by melt electrospinning and 2) piezoelectric composites with tunable electromechanical properties. We will also develop large-scale energy harvesting system using hybrid system of electrostatic and piezoelectric system. For piezoactive fibers, specifically, three research thrusts are proposed: 1-a) Development of helical polymers that can be electrospun after melting, 1-b) establishment of a melt-electrospinning process to transform helical polymer into fiber form to maximize dipole alignment in longitudinal direction, and 1-c) demonstration of working energy harvesting system that incorporates the knowledge gain from the proposed research activities. The fiber-shaped PBLG polymer can be directly patterned on various surfaces including flexible and dielectric substrates, and the energy harvesting effect can be greatly enhanced by increasing the density of the fibers through precise patterning process. To show the feasibility of the proposed system, we will demonstrate that the proposed system can collect enough energy to drive the self-emitting flexible film attachable on the wetsuit, and wireless signal transmitter. The objective of the piezo-composite project is to develop flexible underwater and surface devices with tunable acoustic impedance and bending stiffness for sensing different acoustic signals and harvesting flow-induced energy by investigating polymer-based piezoelectric composites. The composite materials are made of elastic polymer scaffolds (which controls mechanical properties) and piezoactive nanoparticles (control piezoelectricity). This system’s key advantage is the ability to tune the piezoelectric properties because the polymer’s mechanical stiffness is decoupled from the piezoactive components. Here, following activities are proposed: 2-a) fabricate composite materials using molding and 3D pringing, 2-b) investigate material processing parameters (elastomer type, monomer vs. crosslinker ratio, porosity, pore sizes, etc.) of piezoelectric composites to control their acoustic impedance and bending stiffness for using acoustic transducers and energy harvesters in a wide range of conditions, and 2-c) characterize energy harvesting performance of piezoelectric composites for optimization of compositions and geometrical parameters at different flow speeds and/or depth of ocean. The proposed research will provide us key data and understanding about this new material system for acoustic transducers and flow/wind energy harvesters. The outcome of the proposed research will pave ways for the development of new types of acoustic transducer materials that can be utilized in the oceans with a wide range of acoustic impedance values and energy scavenging systems for deployable autonomous sensors tailored for underwater/surface applications. For the large-scale energy harvesting system, we are proposing a new hybrid energy harvesting system utilizing combination and simultaneous use of electrostatic and piezoelectric energy conversion to harvest mechanical energy from low-frequency sources.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 04, 2018
- Source ID
- N000141812796
Entities
People
- Michael Yu
Organizations
- Office of Naval Research
- United States Navy
- University of Utah