Development of piezoeletric structures based on cork and electrospun fibers

• Autor(a) principal: Esteves, David Seixas
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/30802
• topic: Fibers; cork; P(VDF-trFE); electrospinning; piezoelectricity; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais

Growing concern for the environment makes it important to find environment friendly materials and also to use wasted energy to create usable energy. Both can be achieved by using piezoelectric polymers. Poly(vinylidene fluoride-trifluoroethylene), P(VDF-trFE), has good electroactive properties and high piezoelectric constant, also is a lead free material. It is used on sensors, actuators and energy harvesting devices converting wasted energy (vibrations and mechanical impacts) into usable energy. Cork is a natural product with excellent properties as a substrate. It is lightweight, flexible, impermeable and durable. This work aims to develop piezoelectric structures using membranes of P(VDF-trFE) deposited on cork substrate. Electrospinning was used to fabricate P(VDF-trFE) membranes. The polarization of the fibers is achieved during electrospinning and is caused by the strong electric field present. This way in a single step production, is obtained a piezoelectric material and its simultaneous polarization. Using different electrospinning parameters, the membranes were made and characterized. The set of parameters giving rise to membranes with good crystallinity, β-phase and piezoelectric response, were further used to fabricate membranes on cork substrate. This approach is a starting point to design and produce structures that could be used in future applications, such as, sensors and energy harvesting devices.