Electrothermal deterioration factors in gold planar inductors designed for microscale bio-applications

In this study, we present the fabrication of wafer level micro-inductors, designed for contactless neuro-stimulation in vitro, along with an electrothermal study testing the influence of thermal phenomena to their performance. The electrical performance of all micro-scale electromagnetic components is hampered by two dominant factors: Joule heating and electromigration. The scope of the study is to evaluate how these phenomena change the electrical behaviour of the samples during activation. We experimentally define the safe area of operation across six types of samples with different geometric characteristics and we extract useful information for the reliability of the samples by comparing their median failure times. Our findings present the activation restrictions which should be taken into account in order to avoid the thermal degradation of the components, while at the same time could be used as design guidelines for similar geometries.