Resistive switching and long-range filaments in metal/DMSO liquid systems for three-dimensional, multi-terminal connection schemes with on demand dynamic reconfigurability

Abstract: The human brain, with its energy-efficient and massively parallel architecture seamlessly integrates memory and computation. Its topology and functionality serve as the inspiration for the field of neuromorphic computing. Realizing brain-like hardware requires the integration of fundamental properties such as synaptic plasticity, self-organization, hierarchical and modular structures, as well as three-dimensional connectivity. Current challenges lie in developing liquid based neuromorphic material systems with facile fabrication, three-dimensional processing, and brain-like conductivity. This work presents ionotronic systems - i.e., systems that incorporate the movement of both electrons and ions - to obtain dynamically reconfigurable conductive filaments. Our method employs an electrolyte where an anode reservoir produces ions in-situ, enabling electrode-dependent tunability and sustained operation without ion depletion. This manuscript presents four ionotronic systems. Each system grows brain inspired three-dimensional wires contacting two or more electrodes exhibiting resistive switching at connection on a micrometer scale as well as a nanometer scale, demonstrating hierarchical organization and functionality. Furthermore, these conducting filaments are capable of being disrupted by an external electric field or dissolved over time in the ionotronic system, emulating blooming and pruning aspects of plasticity.