This Small Business Innovation Research Phase I project seeks to demonstrate an electro-active polymer-based energy harvesting system to power portable electronics and remote devices. As portable wireless electronics and wireless sensors become ubiquitous, their power sources (batteries) continue to be the limiting factor in their dependability. The ability to harvest enough energy from the motion of a typical portable device to power it has been elusive. Prior efforts have been insufficient primarily due to inefficient energy transfer. Start-of-the-art electro-active polymers (EAPs) and innovative mechanical and electrical impedance matching designs will be used to develop an energy harvesting system with harvested energy density well above standard EAPs. Inefficiencies result from three aspects of the energy harvesting system, mechanical impedance mismatch, electrical impedance mismatch, and inefficient electromechanical conversion material properties. The proposed effort addresses all three of these aspects with a novel electro-active polymer-based energy harvesting system. The system combines recently developed electro-active polymer materials with novel electronic design to maximize the energy transfer from mechanical motion into stored electrical energy.
The broader impact/commercial potential of this project is based on leveraging the unique opportunity for energy harvesting from electro-active polymers developed during the past decade. Heretofore, the potential created by the prior investments into electro-active polymer material development have been unrealized. This project is designed to enhance the understanding of these materials in useful market applications. Two target applications have been chosen based on their potential market size, broad impact, and ability to demonstrate the full capability the electro-active polymer energy harvesting ? 1) button activation on a handheld device and 2) walking motion in the ankle. The button activation is chosen for the large impact it will have in the handheld electronics consumer market. The walking motion application is chosen to demonstrate how an EAP harvesting system can be fully integrated into the functionality of a structure, in this case a prosthetic foot for amputees. Button-push harvesters delivered to consumer electronics OEMs is expected to have a total available market of $100M annually. The walking energy harvesters for prosthetics and portable electronics are expected to have a total available market of $10M annually.
In this SBIR project, KCF Technologies (KCF) teamed with Strategic Polymer Sciences (SPS) to make use of start-of-the-art electro-active polymers (EAPs) and innovative mechanical and electrical impedance matching design to develop an energy harvesting system with harvested energy density well above standard EAPs. As portable wireless electronics and wireless sensors become ubiquitous, their power sources (batteries) continue to be the limiting factor in their dependability. The ability to harvest enough energy from the motion of a typical portable device to power it has been elusive. Prior efforts have been insufficient primarily due to inefficient energy transfer. Electro-active polymer for energy harvesting shows great promise to solve this problem. The direct electro-mechanical coupling eliminates the need for much of the hardware that makes conventional impractical for many applications. Inefficiencies result from three aspects of the energy harvesting system, mechanical impedance mismatch, electrical impedance mismatch, and inefficient electromechanical conversion material properties. All three of these aspects of the technology were advanced in this Phase I project. Energy harvesting was demonstrated on a lab test fixture, the small scale electrical circuitry that provides the electrical boundary conditions to the polymer was designed and built, and mechanical integration into devices was shown. These advances lay the groundwork for the Phase II project. Specifically, integration and testing of high layer count polymer structures is paramount to developing a commercial device. The electronics must also be further reduced in size and cost to become commercially viable, especially for high volume applications. For low volume applications, such as prosthetics, the polymer films are thin enough, and the bias voltage is now low enough that standard components can be used to design the circuitry needed to bias and harvest from the material. A secondary area of research and development in the Phase II project will be towards increasing the efficiency of the harvesting mechanism. The testing here produced about 45% of the theoretical value, an acceptable value for the first prototype. However, future work will be to identify, quantify, and then to design prototypes to eliminate losses.
