Fig. 5: The SIROF electrodes remained stable during in vitro benchtop testing.

a The stability of Pt and SIROF-coated Pt was assessed during 90 h of continuous stimulation surpassing the total stimulation time in vivo (~60 h). In addition, the stability of the SIROF electrodes was tested by mimicking the in vivo treatment of daily 1-h stimulation for 18 days at 55 °C and for 60 days at 37 °C using the same implant body but different electrodes. b SIROF coating enhanced the stability of the electrodes. While the Pt electrode delaminated and dissolved during 90 h of continuous stimulation (Supplementary Fig. 4a), the SIROF electrode stayed intact. c The voltages reached during stimulation are within the water window. d, e Peaks in the CV and EIS indicate a functional SIROF electrode after 90 h of continuous stimulation (n = 3). The changes in the peaks of the CV after stimulation are likely due to the hydration of the SIROF. f SIROF electrodes do not delaminate during the 1-h daily stimulation in accelerated aging regime and in vivo mimicking conditions. f1–3 Representative images of SIROF electrodes, in pristine condition, and after daily 1-h stimulation for 18 days at 55 °C and for 60 days at 37 °C show that the electrodes remained stable. f4 We observed a carbon layer deposited onto electrodes (Supplementary Fig. 4g, 5). g, h CV and EIS recordings of WEs which were stimulated for 60 days at 37 °C. The WEs stimulated consecutively (n = 2) against four shorted CEs remained stable (sample A), while the WE stimulated against two shorted CEs (sample B) remained functional although with carbon deposited at the WE.