Electrical and Mechanical Displacement Measurement

(also known as polarization and strain measurement)

This system measures the electrical and mechanical displacement of dielectric materials induced by an applied AC field. The following properties can be extracted:

  • D-E hysteresis loop parameters, polarization density, energy storage and loss
  • Electromechanical coupling: piezoelectricity, electrostriction, etc.

Measurement Process:

  • Apply AC field to sample
  • Measure sample charge
  • Measure mechanical displacement using a  linear variable differential transformer (LVDT)
Schematic of the measurement system [1] D-E hysteresis loop and polozrization states at different regions [2] Unipolar strain hysteresis loop of poled PZT bulk [3]

Measurement Systems: 

  • Temperature: -100 °C - 150 °C
  • Voltage: ±10V (without amplifier)
  • ± 10kV (with amplifier)

D-E hysteresis loop:
Frequency: 0.001 - 100Hz
Charge: ~10pC to 100mC

S-E hysteresis loop:
Frequency: 0.01 -1Hz
Displacements: > 0.1 µm

 

Figure references:
[1] S. Ahmed et al., Smart Mater. Struct. Vol 23, 2014
[2] An American national standard IEEE standard definitions of terms associated with ferroelectric and related materials, IEEE Ultrasonics Ferroelectrics, and Frequency Control, Vol 50, 2003
[3] W. Zhu et al., IWATMD, 2019