This study presents fabrication of a multilayered, sensor‐integrated brain phantom for validating electric field distributions induced by transcranial electrical stimulation (TES), with an emphasis on long‐term stability and measurement accuracy. The phantom comprises five tissue‐mimicking layers—scalp, skull, cerebrospinal fluid, gray matter, and white matter—each fabricated by doping silicone (polydimethylsiloxane or PDMS) with varying concentrations of multiwalled carbon nanotubes to replicate isotropic electrical conductivity. Embedded sensors at the interfaces enable localized voltage measurements throughout the volume of heterogeneous phantom, without the need for external support structures. Commercial TES electrodes are applied to the scalp layer to replicate stimulation conditions. Interlayer voltage ratios showed a strong agreement between finite element simulation and experiment, with deviations ranging from 0.26% to 10%, indicating preservation of the overall average voltage attenuation across the fabricated tissue‐mimicking layers. Intralayer spatial analysis demonstrated low‐to‐moderate spatial correlation across sensor arrays (Pearson’s r = 0.04–0.58), suggesting that while global voltage attenuation is preserved, accurate modeling of sensor–TMM and TMM–TMM boundary interactions is essential to reproduce local spatial voltage distributions. Together, these findings demonstrate the phantom’s capability for controlled, layer‐specific evaluation of TES‐induced voltage distributions and highlight the importance of detailed geometric and boundary modeling for reliable electric field estimation.
Jain et al. (Thu,) studied this question.