NeurosciencePublished 8 May 2014Electrode impedance analysis of chronic tungsten microwire neural implants: understanding abiotic vs. biotic contributionsViswanath Sankar · Erin Patrick · Robert Dieme · Justin C. Sanchez · Abhishek Prasad · Toshikazu NishidaFrontiers in Neuroengineeringdoi 10.3389/fneng.2014.00013