Physics:Electromechanical coupling coefficient

The electromechanical coupling coefficient is a numerical measure of the conversion efficiency between electrical and acoustic energy in piezoelectric materials. Qualitatively the electromechanical coupling coefficient, k, can be described as:

$k^{-2}=\frac{1}{\text{ energy converted per input energy}}$

References

• "Electromechanical coupling coefficient". GE. http://www.medcyclopaedia.com/library/topics/volume_i/e/ELECTROMECHANICAL_COUPLING_COEFFICIENT.aspx. 
• Vilnius University, Laboratory of Physical Acoustics