The influence of thermo-electromechanical coupling on the performance of lead-free BNT-PDMS piezoelectric composites

Abstract

In recent times, there have been notable advancements in haptic technology,
particularly in screens found on mobile phones, laptops, light-emitting
diode (LED) screens, and control panels. However, it is essential
to note that the progress in high-temperature haptic applications
is still in the developmental phase. Due to its complex phase and
domain structures, lead-free piezoelectric materials such as {\normalsize{}$Bi_{0.5}Na_{0.5}TiO_{3}$}
(BNT)-based haptic technology behave differently at high temperatures
than ambient conditions. Therefore, it is essential to investigate
the aspects of thermal management and thermal stability, as temperature
plays a vital role in the phase and domain transition of BNT material.
A two-dimensional thermo-electromechanical model has been proposed
in this study to analyze the thermal stability of the BNT-PDMS composite
by analyzing the impact of temperature on effective electromechanical
properties and mechanical and electric field parameters. However,
the thermo-electromechanical modelling of the BNT-PDMS composite examines
the macroscopic effects of the applied thermal field on mechanical
and electric field parameters, as phase change and microdomain dynamics
are not considered in this model. This study analyzes the impact of
thermo-electromechanical coupling on the performance of the BNT-PDMS
composite compared to conventional electromechanical coupling. The
results predicted a significant improvement in piezoelectric response
compared to electromechanical coupling due to increased thermoelectric
effect in the absence of phase change and microdomain switching for
temperature boundary conditions below depolarization temperature ($T_{d}\sim200\lyxmathsym{\textcelsius}$
for pure BNT material).