Elastrographic assessment of micromotion-induced strain in tissue adjacent to intracortical implants in rat

Intracortical electrodes are important components of neural interfaces, but are limited in clinical applications due to high rates of device failure. This is in part due to a chronic neuroinflammatory response, which may be a result of mechanical mismatch between stiff implanted devices and the surrounding tissue. In this study, we used ultrasound (US)-based elastography to measure strain maps in vivo around intracortical devices. Experiments were performed by implanting shape memory polymer (soft) and silicon (stiff) devices in rat cortex. The results indicate higher strains in regions-of-interest containing stiff devices, indicating the possible effects of mechanical mismatch on micromotion-induced tissue strain.