Piezoelectric Tensor of Collagen Fibrils Determined at the Nanoscale.

Piezoelectric properties of rat tail tendons, sectioned at angles of 0, 59, and 90° relative to the plane orthogonal to the major axis, were measured using piezoresponse force microscopy. The piezoelectric tensor at the length scale of an individual fibril was determined from angle-dependent in-plane and out-of-plane piezoelectric measurements. The longitudinal piezoelectric coefficient for individual fibrils at the nanoscale was found to be roughly an order of magnitude greater than that reported for macroscopic measurements of tendon, the low response of which stems from the presence of oppositely oriented fibrils, as confirmed here.