High-Performance PZT-Based Stretchable Piezoelectric Nanogenerator

Abstract

Stretchable piezoelectric nanogenerators are highly desirable for power supply of flexible electronics. Piezoelectric composite material is the most effective strategy to render piezoelectric nanogenerators stretchable. However, the generated output performance is unsatisfactory due to the low piezoelectric phase proportion. Here we demonstrate a high-performance Pb(Zr 0.52 Ti 0.48 )O 3 (PZT)-based stretchable piezoelectric nanogenerator (HSPG). The proposed HSPG exhibits excellent output performance with a power density of ∼81.25 μW/cm 3 , dozens of times higher than previously reported results. Mixing technique, instead of conventional stirring technology, is used to incorporate PZT particles into solid silicone rubber. The filler distribution homogeneity in matrix is thus remarkably improved, allowing higher filler composition. The PZT proportion in composite can be increased to 92 wt % with satisfactory stretchability of 30%. On the basis of the excellent electrical and mechanical properties, the proposed HSPG can be attached to human body to harvest body kinetic energy with multiple deformation modes. The obtained energy can be used to operate commercial electronics or be stored into a capacitor. Therefore, our HSPG has great potential application in powering flexible electronics.

Recent progress on flexible nanogenerators toward self‐powered systems

“…[37][38][39][40][41][42] Referring to the deposition method for those piezoelectric thin film or nanocomposite, sol-gel chemistry is no doubt the best route. 43 Taking the most used piezoelectric material, PZT for example, [44][45][46] precursors of lead, zirconium, and titanium are mixed together and dissolved in solvent. The mixed solution is spin-coated on substrates to form a layer of thin film after hydrolysis, followed up with pre-baking for organic residual removal.…”

Skin‐Integrated Graphene‐Embedded Lead Zirconate Titanate Rubber for Energy Harvesting and Mechanical Sensing

“…Thin, soft skin‐integrated electronics have attracted great attentions due to their advantages such as flexible, lightweight, and mechanical compatible with human body, thus offer unique capabilities in detecting vital information and continuous monitoring human health . Recent advances in materials development, electronics miniaturization, mechanics optimization, and system‐level integration build up the foundations for flexible and stretchable electronics which are able to be integrated together with skin. Considering power supply for this new kind of soft electronics, conversion of mechanical energy from human body activities and motions to electricity is a considerable route .…”

“…Among these self‐powered technologies, piezoelectric generators have proven to be a great candidate as energy harvesters for skin‐integrated or even biointegrated electronics, due to the combination of their excellent electrical properties and advanced mechanical designs . Materials and mechanical engineering in piezoelectric materials, including lead zirconate tinanate (PZT), PVDF, BaTiO 3 , NaNbO 3 , and ZnO have been made great progress and realized outstanding electromechanical properties. However, complicated fabrication processes involving high temperature deposition, multiple steps photolithographs, physical/chemical etchings, and transfer printings are typically needed to meet the requirement of flexibility …”

“…To realize rapid and low‐cost processing techniques for soft piezoelectric based electronics, inherent flexibility of the materials should be carefully considered, as which affords the possibility for large‐area fabrication relevant routes, such as screen‐printing and roll to roll technologies . One promising method for realizing inherent flexible piezoelectric materials is designing polymer‐matrix composites which typically consist of piezoelectric ceramic powders and silicone rubbers (polydimethylsiloxane, PDMS) . This kind of composite enables significant decrease of modulus from tens of GPa in pure piezoelectric ceramic to 10 2 –10 4 kPa, and therefore enhance their stretchability .…”

“…One promising method for realizing inherent flexible piezoelectric materials is designing polymer‐matrix composites which typically consist of piezoelectric ceramic powders and silicone rubbers (polydimethylsiloxane, PDMS) . This kind of composite enables significant decrease of modulus from tens of GPa in pure piezoelectric ceramic to 10 2 –10 4 kPa, and therefore enhance their stretchability . However, these reported composites are mostly utilized as strain sensors for mechanical sensing, rather than energy harvesters, which is due to the extremely high internal impedance and very limited current output .…”