SBIR-STTR Award

Performance of conventional primary and secondary batteries improve at a meager rate every year. Sensors and sensor networks which are advancing through relentless miniaturization effects need uninterrupted power sources in many scenarios. We propose to use a piezoelectric based energy scavenging device to harvest energy from environmental vibrations. Although a handful of structures by a few groups have demonstrated that ZnO nanowires have great promise for energy harvesting devices, the few schemes that have demonstrated the energy harvesting in these nanowires have been mainly laboratory experiments performed with an atomic force microscope top or a fiber coated with the ZnO nanowires on which a pulling force is exerted. The proposed work is very necessary to develop more robust schemes that may easily translate to non-laboratory based packages with miniaturized sensors. Phase I will evaluate piezoelectric properties of nanowires of ZnO, GaN, lithium niobate, and PZT design for embedding the nanowire into a softer host matrix to be able to withstand high strains and design a mechanical to energy coupling mechanism with plans to produce a prototype for Phase II.

Keywords:
Energy Scavenge, Piezoelectric Effect, Nanowires, Vibration, Zinc Oxide

The Project Objective is to achieve a piezoelectric energy harvesting device based on nanotechnology-enhanced materials. The power density is expected to achieve ~1-10 mW per cubic mm and are compatible with Army applications in the field to power autonomous miniaturized sensors. The novelty involves synthesizing piezoelectric nanowires, using commercially upscalable techniques, and incorporating the nanowires into nanowire/polymer composites that are suitable for improving the power density beyond previously-achieved results from other groups. The description of the effort can be broken down into four tasks as follows: 1) fabrication of piezoelectric nanowires that possess either high piezoelectric coefficients and/or ease of device integration capabilities, 2) mixing nanowire and polymer matrices to enhance the piezoelectric response in a device structure, 3) prototyping multiple device architectures amenable to high power density generation, and 4) optimizing of device structure. The effort will also encompass the development of novel device architectures that are capable of improving the collection efficiency across multiple vibration ranges (Hz to kHz) as well as vibration direction.

Keywords:
Energy-Scavenging, Energy-Harvesting, Piezoelectric, Nanowires, Vibration, Nanotechnology, Miniaturized Power, Electrospinning