Researchers from Centre for Nano and Soft Matter Sciences (CeNS), in collaboration with scientists from National Chemical Laboratory (CSIR-NCL), Pune have developed a security alert system based on a newly developed piezoelectric polymer nanocomposite.
Piezoelectric materials are those that produce electricity when subjected to mechanical stress (squeezed). The scientists have developed a material that could be used in a walkway, where it could be activated or deactivated. When activated, it can detect anybody walking on it and send a signal.
This development was based on the finding that metal oxide nanomaterials, with appropriate crystal structure and surface properties, when used as fillers in a polymer composite lead to a significant enhancement in the piezoelectric response.
Mechanical energy is plentiful in the world and is easily accessible. It can be converted into electrical energy through a variety of techniques, including contact electrification/triboelectric effect and piezoelectric effect. Flexible, portable, sustainable, and wearable sensors and energy harvesting devices are critical nowadays. Polymers and nanoparticles are playing a major role in present flexible electronic systems.
The researchers prepared synthesized two zirconia-based metal organic frameworks (UiO-66 and UiO-67), which were converted to zirconia nanoparticles by controlling their crystallographic phases.
Polymer nanocomposite films were then fabricated by incorporating these nanoparticles with different crystal structures into a well-known piezoelectric polymer, poly (vinylidene difluoride) (PVDF). Then the team evaluated the influence of varying crystal structures of zirconia nanoparticles on a piezoelectric energy-generating zirconia- PVDF composite. They observed that the surface characteristics and crystal structure of the nanofillers have a significant impact in piezoelectric properties of polymer material, says a press release from the Department of Science and Technology, Government of India.