A review on piezo- and pyroelectric responses of flexible nano- and micropatterned polymer surfaces for biomedical sensing and energy harvesting applications

This review summarises the most recent advances in the application of anodic aluminium oxide (AAO) membranes as templates to prepare poly(vinylidenefluoride)-(PVDF) or poly(vinylidenefluoride-co-trifluoroethylene)-based (PVDF-TrFE) piezoelectric generators, which are typically utilised in biomedical sensing and energy harvesting applications. The significant variation in the electroactive phase content in PVDF or PVDF-TrFE caused by the enhanced polarisation of AAO membranes due to nanoconfinement effect is explored. The literature survey reveals that the energy harvesting and sensing performances of various devices are significantly improved in the nano- and micropillars compared to those of flat films with the same material composition. Thus, nano- and microstructuring of the surface of biocompatible piezopolymers is promising for their applications in various devices for biosensing, strain, pressure thermal or force sensing, piezoelectric generators, microfluidic nano-actuated devices, smart drug-delivery systems, and multiferroic systems.