Heterodyning of signals through physical multiplication is the building block of numerous modern technologies. Yet, it has been mostly limited to the interaction between electromagnetic fields. Here, we report that heterodyning occurs also between acoustic and electric fields in liquid electrolytes. We predict acoustoelectric heterodyning via computational field modelling, which accounts for the vector nature of the electrolytic acoustoelectric interaction. We then experimentally validate the spatiotemporal characteristics of the field emerging from the acoustoelectric heterodyning effect. The electric field distribution generated by the applied fields can be controlled by the propagating acoustic field and the orientation of the applied electric field, enabling the focusing of the resulting electric field at remote locations. Finally, we demonstrate detection of multi-frequency ionic currents at a distant focal location via signal demodulation using pressure waves in electrolytic liquids. As such, acoustoelectric heterodyning could open possibilities in non-invasive biomedical and bioelectronics applications.

通过物理乘法对信号进行外差处理是众多现代技术的基石。然而，它主要限于电磁场之间的相互作用。在这里，我们报告外差作用也发生在液体电解质中的声场和电场之间。我们通过计算场建模预测声电外差，这解释了电解声电相互作用的矢量性质。然后，我们通过实验验证了声电外差效应产生的场的时空特征。由应用场产生的电场分布可以通过传播的声场和应用电场的方向来控制，从而能够将产生的电场聚焦在远程位置。最后，我们演示了通过使用电解液中的压力波进行信号解调来检测远处焦点位置的多频离子电流。因此，声电外差法可以为非侵入性生物医学和生物电子学应用开辟可能性。