Electrostatic Assembly of Laminated Transparent Piezoelectrets for Epidermal and Implantable Electronics

Piezoelectric polymers hold physical properties, such as high mechanical flexibility and smaller acoustical impedance, that piezoelectric ceramics do not have. Nevertheless, owing to the piezoelectricity originates from the crystalline region, it is still a challenge for most semi-crystalline polymers to generate a high piezoelectric response. Here, we develop a class of piezoelectret with sandwiched polymer structure (electret/dielectric/electret, EDE) which is assembled via simple electrostatic interaction. The transparent and mechanical robust EDE piezoelectrets exhibit the piezoelectric constant (d(33)) up to similar to 930 pC N-1, and the corresponding physical model is established to investigate major influence factors to the piezoelectric properties, including the relative permittivity and elastic modulus of the electret and dielectric, and the simulated results are in accord with the experimental data. We demonstrate the strain sensors and acoustic transducers based on the ultrathin and flexible EDE piezoelectret, verifying the feasibility of the electrostatic assembled piezoelectrets in the applications of epidermal and implantable electronics. Moreover, various combinations of polymers in the EDE structure can be employed based on our proposed model to explore other unique applications such as transient electronics.

Automated summary

A class of piezoelectrets with sandwiched polymer structure (EDE) has been developed through simple electrostatic interaction, exhibiting high piezoelectric response, transparency, and mechanical robustness. These EDE piezoelectrets can be used for strain sensors and acoustic transducers, demonstrating high piezoelectric properties.