A Fresh Way to Juice Up Your Devices

Having to frequently recharge all of our electronic devices is right up there with people that take up two parking spots and airplane passengers that remove their shoes on the scale of annoyances. However, barring any unexpected major advances — something like a Back to the Future-style Mr. Fusion or long-distance, wireless transmission of energy — it is something that we will not be able to do away with anytime soon.

But while all those batteries may need more juice, there might be better ways to provide them with it than plugging them into the wall. Energy harvesting technologies, for example, can collect energy that would otherwise be wasted when we move and convert it into electricity to power up our devices. Many such systems exist today, as a matter of fact. So then, why do you still have to plug in your phone every day like a chump? Unfortunately, today’s energy harvesting technologies suffer from a number of problems that greatly limit their range of practical applications.

But that may not be the case for long, as a team led by researchers at the University of Waterloo is experimenting with a new technology that could make energy harvesting far more practical for everyday use. Specifically, they are working with piezoelectric nanogenerators (PENGs), which can utilize the energy contained in ambient vibrations to generate electricity.

Present PENGs can either produce sufficient levels of voltage and current to be useful, or they can be durable, but not both. In either case, you cannot use this technology to build the sort of charging system that would be necessary for use as a commercial device. The novel construction of the team’s device, on the other hand, allows it to produce enough energy to charge electronic devices while at the same time being durable and suitable for real-world use.

The new design incorporates a cascade-type piezoelectric nanogenerator structure using a composite material of polystyrene (PS)-functionalized organometal halide perovskite and polyvinylidene fluoride. PS plays a critical role in enhancing the perovskite matrix by triggering a number of important chemical reactions, improving grain size, reducing defects, and enabling a uniform distribution of halide ions. These features reduce ion migration, improve lattice stability, and enhance crystallinity, resulting in lower dielectric losses and higher dielectric strength. The composite films are assembled in a multilayer architecture with copper electrodes between the layers. Each film is oppositely polarized, and the electrodes connect layers in a parallel configuration to amplify the output current.

The layers are adhered using a solvent-free urethane-based prepolymer to ensure structural integrity and durability. This multilayer stacking approach significantly enhances current density by leveraging multiple interfaces between layers, where polarization changes generate charge. While the piezoelectric potential across individual layers decreases with stacking, the overall current output is multiplied through the interconnected electrodes.

By experimenting with new materials and nanogenerator architectures, the researchers have set a new benchmark for energy harvesting performance and practicality. This advancement holds promise for powering next-generation wearable, flexible, and implantable devices, paving the way for more sustainable and efficient energy solutions in modern electronics.