A |
Surface area [m²] (meter²) |

α |
Coefficient of Thermal Expansion (CTE) [K-¹] (1/kelvin) |

C |
Capacitance (F) [A s / V] |

d_{ij} |
Piezo modulus (tensor components) [m/V] (meter/volt) |

d_{s} |
Distance, thickness [m] (meter) |

Є |
Dielectric constant [A s/V m] (ampere second volt meter) |

E |
Electric field strength [V/m] (volt/meter) |

f |
Operating frequency [Hz] (hertz = 1/second) |

F |
Force [N] (newton) |

f_{0} |
Unloaded resonant frequency [Hz] (hertz = 1/second) |

g |
Acceleration due to gravity: 9.81 m/s² (meter/second²) |

i |
Current [A] (ampere) |

k_{S} |
Stiffness of restraint (load) [N/m] (newton/meter) |

k_{T} |
Stiffness of piezo actuator [N/m] (newton/meter) |

L_{0} |
Length of non-energized actuator [m] (meter) |

∆L |
Change in length (displacement) [m] (meter) |

∆L_{0} |
Nominal displacement with zero applied force, [m] (meter) |

∆L_{t=0.1} |
Displacement at time t = 0.1 sec after voltage change, [m] (meter) |

m |
Mass [kg] (kilogram) |

P |
Power [W] (watt) |

Q |
Charge [C] (coulomb = ampere x second) |

S |
Strain [L/L] (dimensionless) |

t |
Time [s] (second) |

U |
voltage [V] (volt) |

U_{p-p} |
Peak-to-peak voltage [V] (volt) |