Zero-power consuming intruder identification system by enhanced piezoelectricity of K0.5Na0.5NbO3 using substitutional doping of BTO NPs

Abstract

The rapid urbanisation and high population density of all nations requires the development of sustainable security systems at all times which can protect people and their belongings against burglaries. A zero-power consuming or self-powered intruder system (SPIS) was reported for the first time using a flexible piezoelectric composite film nanogenerator (FPCF-NG) made up of polydimethylsiloxane (PDMS) and a solid state reaction (SSR) based dual perovskite system, i.e. (1 − x)K_0.5Na_0.5NbO_3−xBaTiO₃ (adopted as KNN–xBTO, x ≈ 0, 0.02, 0.04, 0.06 and 0.08). Tetragonal phase BTO random nanoparticles (NPs) were doped into orthorhombic phase KNN nanocubes (NCs) without altering the structural properties, enhancing the piezoelectric properties of the parent material. The FPCF-NG device shows excellent flexibility and stability as well as generating a maximum voltage and area power density of 180 V and ≈35 mW m⁻² by applying a 4 N load. The electrical responses of FPCF-NG were evaluated under various conditions such as weight ratio analysis of the composite films (CFs), electrical poling, switching polarity testing, force analysis, capacitor charging, and liquid crystal display (LCD)/light emitting diode (LED) powering. Furthermore, three FPCF-NGs were used to demonstrate the real-time application of SPIS, which can produce a warning alarm/LED glow and display a message on a computer screen upon any intrusion on the device. Hence the work provides an opportunity to construct a potential real-time SMART (Scalable Measures for Automated Recognition Technologies) battery-free security system and its future possibilities in the internet of things.