Highly flexible, biocompatible, large-scale production of BaTiO3 nanocube (BTO NC)/poly­(dimethylsiloxane) (PDMS) composite films (CFs) prepared via a simple, cost-effective solution casting technique are reported for the first time for high-performance piezoelectric nanogenerators (PNGs). The crystalline BTO NCs were synthesized via a simple low-temperature molten salt method. The piezoelectric output performance of the CF was investigated as a function of the weight ratio of the BTO NCs in the polymer matrix, electrical poling, constant mechanical loading, and low-frequency biomechanical energy harvesting. The composite PNG (CPNG) with 15 wt % of BTO NCs displayed an excellent peak-to-peak voltage (V pp) of 126.3 V and current density (J) of 77.6 μA/cm2 and generated a maximum instantaneous areal power density of 7 mW/cm2 at 100 MΩ at the low input mechanical pressure of 988.2 Pa. The generated output was sufficient to drive commercial light-emitting diodes and low-powered consumer electronic devices. Next, the CPNG was tested to harness waste biomechanical energy in our daily life; it generated a V pp of 29 V (human hand palm force) and 55.9 V (human foot stress). The proposed device was lightweight, flexible, eco-friendly, cost-effective, and a potential candidate to generate high electrical output at low mechanical pressure.

In contrast with the conventional ceramic/oxide humidity sensors (HSs), a self-powered piezoelectric biopolymer HS with reasonable sensitivity, reliability, and a nontoxic and eco-friendly nature is highly desirable. A piezoelectric nanogenerator (PNG)-driven biopolymer-based HS provides a pathway toward a sustainable and greener environment in the field of smart sensors. For that, a piezoelectric collagen nanofibril biopolymer coated on to a cotton fabric has dual functionality (energy harvesting and sensor). Collagen PNG generates a maximum of 45 V/250 nA upon 5 N and can also work as a sensor to measure various percentages of relative humidity (% RH). The HS shows a linear response with a good sensitivity (0.1287 μA/% RH) in the range of 50-90% RH. These results open a field of eco-friendly multifunctional nanomaterials toward the development of noninvasive, implantable smart bio-medical systems.

No abstract

No abstract

A water proof silicone elastomer based triboelectric nanogenerator for bio-mechanical energy scavenging and a zero-power consuming/self-powered pressure sensor.