Evaluation of CoFeSiB microwires for biomechanical stress studies

In this paper, we evaluate and discuss the application of amorphous glass-covered microwires for biomechanical stress studies. The dependence of the magnetoinductance, of amorphous glasscovered magnetic CoFeSiB microwires upon the application of a force perpendicular to their longitudinal axis was studied. This principle could be used to estimate loads in biological tissues such as muscles, tendons and ligaments. For example, a loaded tendon will elongate, leading to a longitudinal and negative transverse strain (the Poisson effect). The tendon's collagen fibers will consequently squeeze an implanted microwire and the wire's inductivity will change. As an example of a practical application, stress measurements were performed using porcine achilles tendons. Results are presented indicating the sensitivity and optimum electrical parameters of the microwires when used as a biomechanical load sensor.