Energy Harvesting and Storage for Low Frequency Vibrations.

Energy harvesting at low frequency has proven to be difficult to achieve in the past because of the properties of the materials that the devices are fabricated from. In particular the stiffness of conventional silicon and all piezoelectric materials makes it exceedingly difficult to make a system that can operate below 100Hz. There are many sources of low frequency vibrations e.g. human motion, the motion of ships, and traffic; so an Energy Harvester that can operate in this frequency range would have a large commercial potential and extensive opportunities for future exploitation. This multi disciplinary project proposal addresses the lack of durable energy harvesting systems in this frequency range. With primary objectives of the project being the development of materials and devices for Low frequency tunable energy harvesting device and High energy density compact supercapacitors for energy storage with secondary objectives being:

• The necessary electronics to connect them and make them work efficiently
• Packaging technologies that will integrate the full system and make it biocompatible
• A study of component reliability and models that can project their lifetime
• An end of life study and an environmental impact assessment

Perpetually self powered electronic systems that can be implanted into the human body is the application area that we have targeted for demonstration of this technology, because there are a clear set of requirements which will motivate the design, fabrication and test of the system under consideration. The two primary objectives present a range of novel and substantial materials challenges in both making the components, achieving a reliable unattended operational extended lifetime and ensuring that the devices are not toxic to the host that they are implanted into. While the secondary ones will facilitate an appropriate demonstration of the technology and ensure its usefulness after the project has been completed.