Using Tendon Inherent Electric Properties to Consistently Track Induced Mechanical Strain

Abstract

The present work explores the possibility that the inherent electrical properties of a tendon might allow it to act as its own strain gauge. Tendon has been shown to exhibit piezoelectric effects as well as streaming potentials when subjected to a mechanical stress. To assess the feasibility of using these properties to repeatably measure in situ strain,bovine Achilles tendon test specimens were connected in series with a control resistor in a direct current circuit. Longitudinal(along the collagen fiber direction) and transverse test specimens were subjected to sinusoidal tension while electrical resistance data for the specimens was collected. Change in resistance per unit strain and gauge factors (GFs) revealed a repeatable and significantly different correlation between resistance and strain for the longitudinal and transverse specimens (p<0.001). Change in resistance per unit strain values for longitudinal and transverse specimens were 0.85 and 1.76 MX/e, respectively while corresponding GFs were 0.52 and 0.74, respectively. Others have reported piezoelectric mechanisms and streaming potential mechanisms in hydrated collagen, however the present work is unique in presenting an accurate and repeatable model of anisotropic tendon behavior that could be used to develop an in situ strain sensor.

Piezoelectric Nano‐Biomaterials for Biomedicine and Tissue Regeneration

“…Similar to bone and cartilage, dense, highly aligned, piezoelectric collagen fibrils are mainly responsible for mechanotransduction (by developing streaming potential) in tendon/ligament (T/L) tissues. [105] Therefore, structural hierarchy and integrity of T/L tissues are highly essential for smooth functioning, which is often disrupted by overloading, thereby leading to tearing or rupturing of tissue. Like cartilage, T/L possesses poor regenerative capacity since they lack adequate reparative cell population and blood vessels.…”

“…The tendon is an important load‐bearing tissue involved in transmission of tensile forces between muscle and bone, where the ligaments maintain the stability of joints. Similar to bone and cartilage, dense, highly aligned, piezoelectric collagen fibrils are mainly responsible for mechanotransduction (by developing streaming potential) in tendon/ligament (T/L) tissues 105. Therefore, structural hierarchy and integrity of T/L tissues are highly essential for smooth functioning, which is often disrupted by overloading, thereby leading to tearing or rupturing of tissue.…”

Electroactive Biomaterials and Systems for Cell Fate Determination and Tissue Regeneration: Design and Applications

“…Collagen as an ECM protein contributes to the piezoelectric effect of many animal tissues, including bones, hairs, tendons, ligaments, skins, callus and cartilages. [ 8a,b,53 ] Elastin as another ECM protein contributes to the piezoelectricity in blood vessels. [ 49b,54 ] The function of natural piezoelectricity remains elusive, but it is generally considered to be closely associated with many physiological processes, tissue growth and remodeling.…”

Piezoelectric polymers as biomaterials for tissue engineering applications

“…Due to their collagenous structure, tendons and ligaments also exhibit piezoelectricity, giving rise, therefore, to an electrical potential variation when a mechanical stress is applied [75][76]. The piezoelectricity of dry tendons was measured [77], as well as the electrical potentials generated in hydrated tendon [78][79], the piezoelectric coefficient decreasing with increasing hydration [80].…”