Piezoelectric Sports Nets: Energy-Harvesting Athletic Equipment

The table of contents begins with an Introduction that provides an overview of piezoelectric energy harvesting and its significance in wearable technology. This is followed by a section on Piezoelectric Materials, which discusses both inorganic materials such as Zinc Oxide (ZnO) and Lead Zirconate Titanate (PZT), as well as polymer materials like Polyvinylidene Fluoride (PVDF) and its copolymers, along with bio-piezoelectric materials. Next, the document covers Sports Nets Design and Fabrication, detailing flat plate designs, curved structures, and various fabrication methods including hydrothermal synthesis, electrospinning, and printing transfer techniques. The section on Energy Harvesting Performance explores kinetic energy generated by athletes through force analysis and energy calculations, alongside vibrational energy harvested from fans, emphasizing footfall rates and walking speeds. The Applications section outlines the use of piezoelectric technology in medical fields, such as arterial pulse monitoring and deep brain stimulation, as well as in sports performance for muscle monitoring and ball speed detection. It also highlights other innovative applications like wind energy harvesting and self-powered pacemakers. In the Challenges and Future Work section, the document addresses key challenges such as device performance limitations, reliability concerns, integration with electronics, and issues related to wearability and material optimization. The Conclusion summarizes the progress made and outlines future directions for research and development. Finally, a section of FAQs provides concise answers to common questions about piezoelectricity, materials, energy harvesting mechanisms, performance factors, applications, and ongoing challenges in the field.

With the fast improvement of compact and wearable electronic gadgets, reaping surrounding energy from human exercises and substantial movements has arisen as a promising answer for power these gadgets. Piezoelectric energy collectors specifically stand out because of their capacity to change over mechanical vibrations and stresses into power straightforwardly. This survey plans to give knowledge into ongoing progressions in piezoelectric energy collectors and their possible applications. The functioning standard of piezoelectricity where mechanical anxieties produce charges in specific strong materials is first presented. A few normally utilized piezoelectric materials are then examined, including inorganic materials like PZT pottery and ZnO, as well as the natural polymer PVDF. Methodologies to manufacture these materials into energy reapers are likewise inspected. Factors impacting gatherer execution like material properties, gadget designs, and procedures to further develop effectiveness are investigated. Different applications are summed up, from driving sensors and wearables to gathering energy from modern cycles. At last, flow difficulties and future bearings are framed to advise the proceeded with advancement and interpretation regarding piezoelectric energy gathering. By examining key parts of piezoelectric gatherers, this survey expects to act as a valuable presentation and reference in this quickly propelling field.

A pursuit of information shows that worldwide interest in “piezoelectric energy collecting” has developed considerably beginning around 2004, exhibiting expanded thoughtfulness regarding this field. From January 2004 to November 2022, looks for this term rose more than 400%. There was major areas of strength for especially starting around 2010, agreeing with progresses in adaptable gadgets and wearables driving interest for self-fueled advancements. The related query “piezoelectric materials” shows a steady volume of searches historically, suggesting consistent interest in the fundamentals. More searches are conducted from developed countries like the United States, United Kingdom, Germany, Japan and South Korea compared to other parts of the world. These countries tend to be innovation hubs for piezoelectric applications. When analyzed by industry, searches are disproportionately from the engineering and electronics sectors, which aligns with piezoelectricity’s uses in sensors, actuators and energy devices. Academia also accounts for a notable portion of searches, indicating significant research activity. In summary, search data reflects considerable and increasing global interest in piezoelectric energy harvesting technologies over the past two decades. This growth has coincided with advancements enabling new applications, supporting the importance and future potential of this field.

Piezoelectric Materials

Piezoelectric materials can be by and large arranged into inorganic and natural materials in light of their synthetic organization. Inorganic materials researched broadly incorporate ZnO and lead zirconate titanate (PZT) pottery, while polyvinylidene fluoride (PVDF) is a regularly utilized natural piezoelectric polymer.

Inorganic piezoelectric materials

ZnO

ZnO has a wurtzite precious stone construction which comes up short on focus of evenness, permitting it to produce electric charges in light of mechanical strains. It is a generally read up piezoelectric material for its high piezoelectric coefficient, minimal expense, and simplicity of synthesis into different nanostructures. Various morphologies of ZnO including nanowires, nanoparticles, and nanosheets have been accounted for energy collecting applications.

PZT

Lead zirconate titanate (PZT) is another widely considered ferroelectric earthenware material because of its high piezoelectric coefficients around 500-600 pm/V. PZT exists in both mass and dainty film structures which can be created by strong state response sintering, sol-gel handling, faltering and so forth.

Other materials

A few other piezoelectric fired materials with perovskite structure incorporate BaTiO3 and lead magnesium niobate (PMN) strong arrangements. Other crystals, as well, such as lithium niobate (LiNbO3) and lithium tantalate (LiTaO3) single valuable stones exhibit excellent piezoelectric characteristic. The same can be said for Zinc sulfide (ZnS) and gallium arsenide (GaAs).

Polymer piezoelectric materials

PVDF

PVDF is the most generally utilized piezoelectric polymer because of its adaptability, low thickness, non-harmfulness and great mechanical properties. Different structures including films, powders, filaments and extended PVDF layers have been created.

PVDF copolymers

Examples of copolymers are poly (vinylidene fluoride-trifluoroethylene) P(VDF-TrFE) and poly (vinylidene fluoride hexafluoropropylene P(VDF-HFP) prepared via the expansion of TrFE or HFP monomers. They can enhance the β-phase content and piezoelectric properties compared to pure PVDF.

Bio-piezoelectric materials

Some protein structures like collagen fibrils in bone or tendon, and chitin in crustaceans shells have been found to exhibit piezoelectricity. Their nanostructures and crystalline organizations lead to piezoelectric dipoles.

Redes de desporto Design and Fabrication

Flat plate design

A typical and straightforward design for piezoelectric energy reapers is the flat plate structure. It comprises of piezoelectric materials, for example, piezoceramic circles or PVDF foils joined to an inflexible substrate with metal cathodes on the two sides. When subjected to external mechanical force, the piezoelectric material bends and induces strain on the surfaces to generate surface charges. Multiple piezoelectric foils can be stacked in parallel to increase output.

Curved structures

Curved structures with bending motion can produce larger strain compared to flat structures, resulting in higher output performance. Common designs include piezoelectric ribbons, cymbal-shaped structures, and fusiform structures. The curved substrate can intensify the strain of the piezoelectric layer when force is applied.

Fabrication methods

Hydrothermal synthesis

Hydrothermal synthesis is a minimal expense arrangement based technique for creating different 1D nanostructures, for example, nanowires and nanorods of piezoelectric semiconductors. By controlling temperature, pH worth, and development time, morphologies can be controlled.

Electrospinning

Electrospinning is capable of producing long continuous ultrafine fibers with diameters from microns to nanometers. It has been widely used to synthesize 1D piezoelectric polymer fibers for energy harvesters by adjusting synthesis parameters.

Printing transfer

Printing-transfer based assembly provides an accurate and high-yield approach for dense arrays and patterned structures. The piezoelectric/substrate can be printed and transferred layer by layer with controlled registration.

Energy Harvesting Performance

Kinetic energy from athletes

Force analysis

To estimate the kinetic energy generated by athletes, literature on force measurements from various athlete biomechanics studies are reviewed. Force plate testing provides data on ground reaction force that quickly rises and falls, forming an impact peak. Studies find forces from 1.6-2.3 times body weight during running. Forces depend on variables like anatomy, muscle strength, speed, and movement type.

Energy calculation

Using the average player weight of 248 lbs from a Scripps Howard study, the corresponding mass is 112.49 kg. With gravitational acceleration of 9.80 m/s2, the player mass is 1,102.41 N. To calculate the kinetic energy generated, the acceleration rate needs to be determined. Several studies break down the acceleration rate athletes reach maximum velocity. Using a maximum velocity of 28 feet/second reached 27.34 yards and acceleration time of 3.28 seconds, the acceleration rate is calculated as 8.52 m/s2. Plugging into the kinetic energy equation, the force per step is estimated as 6,990.87 N.

Vibrational energy from fans

Footfall rate and walking speed

To estimate fan footfall, studies on average walking speeds are reviewed. Based on 7,123 pedestrians examined, the average walking speed for elderly (51.45% of total) was 4.11 feet/second, while the remaining pedestrians walked at 4.95 feet/second. It takes 3.75 seconds for the elderly to reach average speed, and 3 seconds for the remaining pedestrians.

Energy harvesting from footfall

Using the estimated average walking speed and acceleration time, the velocity at 27.34 yards when maximum speed occurs can be calculated as 28 feet/second. The time taken to reach this speed for an average pedestrian is 3.28 seconds. Based on this, the acceleration rate is calculated as 8.52 m/s2. Applying this acceleration rate to the mass of an average human, the force per step is estimated as 6,990.87 N. Using the force per step and rate determined from the Pavegen experiment of generating 7 watts per step, the energy generated by an average fan per step is estimated.

Aplicações

Medical applications

Arterial pulse monitoring

Wearable piezoelectric devices have been developed to non-invasively monitor arterial pulse waves, which provides important information for cardiovascular diagnosis and treatment. A flexible composite made of PVDF and ZnO NWs shows potential as a self-powered pulse pressure sensor with output voltage and current reaching 5 mV and 1.8 μA at the radial arterial position.

Deep brain stimulation

Piezoelectric materials like PIN-PMN-PT have been used in deep brain stimulation devices to induce contraction of forelimb muscles in mice, demonstrating their efficacy in neurological applications like seizure control and pain relief.

Sports performance

Muscle monitoring

Wearable piezoelectric sensors have potential applications to monitor muscle activity and movement by detecting electromyography (EMG) signals. A sensor made of alumina microfibers/PDMS detects biceps muscle activity with high sensitivity and durability.

ball speed detection

Sports venues have explored using piezoelectric materials like PZT to measure impact forces on rackets/bats or rotation speed of balls like tennis serves to analyze performance. Output correlated well with measurements from high-speed cameras.

Other applications

Wind energy harvesting

Macrofiber composite transducers bonded with serrated wings have been proposed as piezoelectric generators installed at the center of wind turbine fans/nozzles to harvest airflow energy indoors from 0-35 Hz at velocities up to 10 m/s.

Self-powered pacemaker

Leadless pacemakers powered by piezoelectric nanogenerators in the form of flexible harvesters have been implanted in animal models as a potential replacement for battery-powered devices eliminating replacement surgery.

Challenges and Future Work

While significant progress has been made in piezoelectric energy harvesting, several challenges still remain before widespread applications can be realized. Device performance presents one key challenge. The power densities achieved by generators are still relatively low, limiting application to small-scale sensor nodes rather than more power-hungry devices. Improving efficiency through material property optimization and harnessing multiple energy sources could help address this. However, advanced materials synthesis and complex device designs increase costs. Reliability is another concern, as long-term stability under cyclic loading and environmental exposure must be ensured. Characterization of fatigue lifetimes under different operating conditions would support reliable product design. Integration with electronics is challenging due to impedance mismatches. Efficient power management circuitry is critical but increases system complexity. Adapting harvesting to direct charge storage without conversion losses could simplify designs. Wearability also requires soft, stretchable and biocompatible substrates that maintain performance over cycles of deformation. Multifunctional composites integrating piezoelectrics with polymers offer a promising solution but properties must be optimized. Standardization of test protocols would streamline comparison between research. Inclusion of real-world energy sources and longer term testing would better evaluate feasibility. Going forward, address these challenges through advanced materials, mechanically optimized designs, simplified power circuits, and standardized performance benchmarks could accelerate commercialization. Fully exploiting piezoelectricity requires continued exploration at the nanoscale towards single-crystal films with enhanced properties.

Conclusão

Piezoelectric energy reaping has considered huge headway as of late to be a promising answer for driving convenient hardware through encompassing mechanical vibration. This innovation takes advantage of the piezoelectric impact to change over mechanical strain into power straightforwardly. Different piezoelectric materials including pottery, polymers and nanostructures have been investigated for use in energy gatherers. Much progress has also been made in device designs and approaches to improve performance. However, to fully realize the potential of piezoelectric energy harvesting, further work is still needed. Output power densities remain relatively low for practical applications beyond small wireless sensors. Reliability also needs improvement through optimization of materials properties and device stability over cyclic operation. Integration challenges such as impedance matching and voltage conversion also require attention. The review explores structural designs, fabrication techniques, performance improvement strategies and applications of piezoelectric energy harvesters. Special focus is given to flexible energy harvesters using materials like PVDF and ZnO, with potential in next-generation wearable devices. While significant advancements have been made, continued efforts in high-performance materials, mechanically optimized designs and simpler power conversion circuits will help accelerate the commercialization of piezoelectric energy harvesting. Realizing its full possibilities will require addressing current challenges through ongoing multidisciplinary research.

FAQs

Q: What is piezoelectricity?

A: Piezoelectricity means that an external force, mechanical or electric, results in the development of charge in the material it has been applied to, or that it changes dimension in a specific electric field. Located in materials require acenter of balance at the nuclear scale such as ceramics, gem and organic.

Q: List a few piezoelectric materials, what are typical examples?

A: Common piezoelectric materials includes gems like quartz and manufactured matrices which includes lead zirconate titanate (PZT) pottery, barium titanate, zinc oxide, aluminum nitride, polyvinylidene fluoride (PVDF) and copolymers thereof.

Q: What powers a piezoelectric energy gatherer?

A: Piezoelectric materials, in general, give rise to an electric charge in response to mechanical strain proportionate to the applied pressure. In a piezoelectric energy gatherer, this charge is accumulated and taken to anMV device. Normal designs utilize the material in a cantilever or cymbal setup to change over encompassing vibrations into atensile or compressive strain to prompt charges.

Q: What variables influence gatherer execution?

A: Execution relies upon material properties like piezoelectric coefficient, terminal design, aspects, pre-burden or verification mass utilized. Diminishing inside/outside screening impacts through material/interface designing further develops execution.

Q: What are a few utilizations of these gatherers?

A: Applications incorporate fueling LEDs, little hardware, remote sensor hubs by reaping from strides, body developments, modern vibrations and that’s just the beginning. They are especially encouraging for self-fueled wearables and IoT gadgets.

Q: What are the principal challenges remaining?

A: Key difficulties incorporate low result power densities, unwavering quality over cyclic use, impedance matching troubles, restricted recurrence reaction ranges. Blending materials properties, gadget models and power circuits could assist with addressing the difficulties to speed up commercialization.