Statistical characterization of piezoelectric coefficient d23 in cow bone

In a newly developed, highly sensitive dilatometer we applied pulsatile electric fields to five dry bone samples cut from mid-tibial sections within a 90 degrees angle from the rear to front axis. Samples of five cows were studied. We measured the piezoelectric coefficient d23 establishing its mean and confidence interval for the first time. An analysis of variance detected a significant difference of the coefficient between animals (P < 0.01) but not between samples (P = 0.5). Between animals the coefficient ranged from 9.6 x 10(-14) to 27.1 x 10(-14) C/N. It can no longer be assumed that piezoelectricity is an inherent property of bone, constant between animals.