Tom MaltbyElectronic and Electrical Engineering PhD
Piezoelectric energy harvesting
The work displayed here is just a small part of a larger PhD research project. The research is focused on piezoelectric energy harvesting using a polymer called Polyvinylidene fluoride (PVDF). When processed in a certain way PVDF becomes a piezoelectric material; this means that when it is vibrated, stressed or compressed, it generates an electric charge between its top and bottom surface. This charge can be collected using electrodes bonded to the surface of the PVDF and used as a conventional voltage/current source once put through a special circuit. Being able to use this waste energy is of great benefit for many applications. A good example of this is hard-to-reach wireless sensing nodes which would require a lot less maintenance if the batteries did not have to be replaced. The main aim of the research is to use this novel polymer to build devices which can collect waste energy from different sources. These can be natural sources or man made; it doesn't matter as long as the devices are put under stress or vibrated. The main focus points for the project have been the development of advanced processing techniques to easier produce the polymer in different forms as well as equipment to test the produced devices. For example, films around 100_m thick are made from 500nm to ~3_m fibres that are randomly deposited on top of each other to form the film. Also, experiments that wrap these tiny fibres around a central electrode have been developed to create composite fibres.