Nanotubes in Polymers for Energy Conversion – NAPOLECO

The proliferation of wearable and consumer electronics, as well as integrated systems, has raised the issue of powering up such devices. In particular, the use of primary batteries raises many issues, such as maintenance cost due to their limited lifespan and environmental concerns because of their complex recycling process. Hence, it has recently been proposed to use environmental sources for supplying electronic systems. In particular, vibrations are one of the most commonly available sources for energy harvesting. While many works in this field focused on piezoelectric materials, these latter feature drawbacks such as limited strain abilities and complex manufacturing process. In contrast, electroactive polymers (EAP) present high flexibility, and can be processed in various shapes. However, their conversion abilities are still far lower than piezoelectric materials. Therefore, it is mandatory to explore new ways for magnifying the ability of EAPs for converting mechanical energy into electricity, through the elaboration of new compositions or by the use of proper electronic interfaces. The aim of the proposal is to optimize the development of new nano-filled polymer composites for energy harvesting on ambient sources. These new nano-filled polymer composites will be prepared by dispersing functionalised carbon nanotubes within a polymer matrix. They will be characterized at various scales (from nano-scale to macro-scale). This characterization includes imaging (interaction between the nanofillers and the matrix, interaction between the composite and its electrodes) and measurement of the macroscopic conversion properties (i.e. electrostrictive coefficient Q or M, harvested current or power under thermal gradient and mechanical vibration, relevant electrical and mechanical parameters (permittivity, percolation threshold, Young modulus, etc.)). This project will support the on-going and worldwide effort for optimizing the conversion efficiency by a better understanding of the mechanism of conversion from nano-scale to macro-scale and to develop new harvester systems using thermal and mechanical ambient sources. This project will help to develop new self powered, autonomous wireless and friendly environmental smart systems (i.e. health monitoring systems, autonomous sensors…) and will also contribute to a rational use of energy and to the reduction of batteries needs.