Photo: Prof Amanda Ellis, Head of Department for Chemical Engineering at the University of Melbourne, Australia
On 5 November 2020, CHEMMAT PhD students and staff connected remotely with Prof Amanda Ellis for our first lunchtime webinar. As well as giving us an overview of their current activities and programmes at Chemical Engineering at the University of Melbourne, Amanda spoke about her research on Nanomaterial dipole templating in 3D printed composite flexible piezoelectric energy harvesters.
While solar and wind dominate the large-scale energy sectors, greater emphasis should be placed on personal-scale energy production, such as piezoelectricity. Piezoelectricity harvests mechanical energy and is particularly useful for portable, wearable and implantable electronics. Polymeric piezoelectric materials, namely fluoropolymers (e.g. poly(vinylidene fluoride), PVDF) are light weight, flexible and transparent, but require highly energetic processing to achieve favourable mechanical to electrical conversion efficiencies, limiting application.
The talk highlighted current work that demonstrates the use of shear-induced alignment through 3D printing of a copolymer of PVDF, poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE), in the presence of 1D (carbon nanotubes) and 2D (mXene) nanomaterials. The shear-alignment along with surface properties of the nanomaterials imparts dipole templating and dipole alignment of the piezoelectric polymer. This alignment, predicted by molecular dynamics models for short-range interactions, improves energy harvesting and decreases the energy input for the manufacture of flexible piezoelectric energy harvesting. The composites produced through this method are fully recyclable in acetone and can be reprinted into various form factors without loss of performance, enabling future use for designer energy harvesting systems. I will also discuss recent work it developing 3D printed dehydrofluorinated porous membranes with potential piezoelectric activity.
Read more about Prof Ellis and her research here