Enhanced torsional actuation and stress coupling in Mn-modified 0.93(Na0.5Bi0.5TiO3)-0.07BaTiO3 lead-free piezoceramic system

Pelin Berik; Deepam Maurya; Prashant Kumar; Min Gyu Kang; Shashank Priya

doi:10.1080/14686996.2016.1254569

Enhanced torsional actuation and stress coupling in Mn-modified 0.93(Na_0.5Bi_0.5TiO₃)-0.07BaTiO₃ lead-free piezoceramic system

Sci Technol Adv Mater. 2017 Jan 9;18(1):51-59. doi: 10.1080/14686996.2016.1254569. eCollection 2017.

Authors

Pelin Berik¹, Deepam Maurya¹, Prashant Kumar¹, Min Gyu Kang¹, Shashank Priya¹

Affiliation

¹ Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech , Blacksburg , VA , USA.

Abstract

This paper is concerned with the development of a piezoelectric d₁₅ shear-induced torsion actuator made of a lead-free piezoceramic material exhibiting giant piezoelectric shear stress coefficient (e₁₅) and piezoelectric transverse shear actuation force comparable to that of lead-based shear-mode piezoceramics. The Mn-modified 0.93(Na_0.5Bi_0.5TiO₃)-0.07BaTiO₃ (NBT-BT-Mn) composition exhibited excellent properties as a torsional transducer with piezoelectric shear stress coefficient on the order of 11.6 C m^-2. The torsional transducer, consisting of two oppositely polarized NBT-BT-Mn d₁₅ mode piezoceramic shear patches, provided a rate of twist of 0.08 mm m^-1 V^-1 under quasi-static 150 V drive. The high value of piezoelectric shear d₁₅ coefficient in NBT-BT-Mn sample further demonstrated its potential in practical applications. These results confirm that the lead-free piezoceramics can be as effective as their lead-based counterparts.

Keywords: 10 Engineering and structural materials; 107 Glass and ceramic materials; 202 Dielectrics/Piezoelectrics/Insulators; 304 Powder processing/Sintering; 400 Modeling/Simulations; Lead-free; actuation; piezoceramic; shear-mode; torsion.