The triboelectric effect is one of the most trending effects in energy harvesting technologies, which use one of the most common effects in daily life. Herein, an impervious silicone elastomer-based triboelectric nanogenerator (SE-TENG) is reported with a micro roughness-created silicone elastomer film and Ni foam as triboelectric layers with opposite surface charges. The surface roughness modification process was performed via a cost-effective soft lithography technique using sandpaper. The replicated film was then used as the negative triboelectric layer and porous Ni foam was used as the positive triboelectric layer. The device exhibited the advantage of high stability due to the porous nature of the Ni foam, which could not damage the roughness pattern of the elastomer film. The device generated a maximum electrical output of ∼370 V/6.1 μA with a maximum area power density of ∼17 mW m⁻² at a load resistance of 1 GΩ. Furthermore, the SE-TENG device was packed using polyethylene to protect it from humidity and made to be a water-resistant SE-TENG (WR-SE-TENG). The device was stable under different percentages of relative humidity, showing a uniform electrical output in the range of 10% RH to 99% RH. This proves that the packing is highly resistant against moisture and humidity. The device was also used for demonstrating its capability in powering small electronic components such as charging commercial capacitors, glowing LEDs and powering wrist watches. Further, the WR-SE-TENG device was used to scavenge bio-mechanical energy from human motions and also used for a real-time application of zero power consuming/self-powered pressure sensors. As an active sensor, the device showed linear sensing behavior and a sensitivity of 0.492 μA kPa⁻¹.

Flexible, planar composite piezoelectric nanogenerators (C-PNGs) were developed to harness waste mechanical energy using cost-effective composite films (CFs) prepared via a probe-sonication technique. CFs, made up of highly crystalline, randomly oriented lead free piezoelectric nanoparticles (1 − x)K_0.5Na_0.5NbO₃-xBaTiO₃, where x = 0.02, 0.04, 0.06, or 0.08 [designated as KNN-xBTO], were impregnated in a polyvinylidene fluoride (PVDF) matrix. The KNN piezoelectric properties were tuned via the substitution of BTO nanoparticles, without altering the orthorhombic phase. A C-PNG device (x ≈ 0.02) generates a maximum open circuit voltage ≈160 V, and the instantaneous area power density is ≈14 mW m⁻² upon a low mechanical force ≈0.4 N. The effects of BTO concentration in the KNN lattice, electrical poling effects, the fixed weight ratio of nanoparticles in the PVDF matrix, switching polarity tests, and load resistance analysis of C-PNG devices were investigated with constant mechanical force. Furthermore, the experimentally demonstrated C-PNG device output is sufficient to drive commercial blue light emitting diodes. The C-PNG device was placed on a road side, and the maximum energy generation and stability under real time harsh conditions, such as vehicle motion (motorcycle and bicycle) and human walking, were tested. C-PNG generates a peak-to-peak output voltage ≈16 V, when motorcycle forward/backward motion acts on it. This result indicates that the C-PNG device is a potential candidate to power road side sensors, speed tachometers, light indicators, etc. on highways.

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.