From solid to liquid piezoelectric materials

Area of Science:

• Materials Science
• Condensed Matter Physics
• Fluid Dynamics

Background:

• Piezoelectricity, the generation of electric polarization by mechanical stress, was discovered in ferroelectric crystals.
• The phenomenon is defined by the linear coupling between mechanical stress and electric polarization, encompassing direct and converse effects.
• Analogous effects have been observed in various materials lacking inversion symmetry, including polymers and biomaterials.

Purpose of the Study:

• To review the historical evolution of piezoelectricity.
• To explore the emergence of liquid piezoelectricity in ferroelectric nematic liquid crystal (NF) materials.
• To analyze direct and converse piezoelectric measurements in NF materials and discuss future applications.

Main Methods:

• Historical review of piezoelectricity research.
• Analysis of electromechanical effects in chiral liquid crystals and NF materials.
• Summary and analysis of direct and converse piezoelectric measurements in NF materials.

Main Results:

• Piezoelectricity has evolved from solid-state phenomena to include liquid piezoelectricity in NF materials.
• NF materials exhibit direct and converse piezoelectric effects despite being three-dimensional fluids.
• Steady stress in NF materials is sustained by surface tension, unlike in some crystalline materials.

Conclusions:

• Liquid piezoelectricity in NF materials represents a significant evolution of the piezoelectric concept.
• Further research on NF materials is needed to overcome challenges and unlock potential applications.
• The study of liquid piezoelectricity opens new avenues in materials science and electromechanical devices.