Temporal interference transcranial alternating current stimulation (TI-tACS) does not readily enable synchronous cross-plane modulation of multiple brain regions in three-dimensional space. To address this challenge, this study proposes a three-dimensional (3D) cross-plane multi-target simultaneous stimulation strategy based on electrode spatial topology. Without increasing the number of electrode groups, the proposed strategy enabled cooperative target formation on multiple planes. Predictable multi-target shifts were achieved by adjusting the current-amplitude ratios across channels. Simulations showed that the strategy stably generated multi-target simultaneous stimulation and exhibited good independent controllability, as evaluated by off-target displacement. A multichannel TI-tACS stimulator was developed and was validated in a saline phantom experiment, where the target formation and shift trends agreed with the simulation results. This work provides an engineering reference for electrode configuration and parameter design for 3D cross-plane multi-target neuromodulation.
