Investigating Volatile Resistive Switching in Organic Gel Electrolyte Memristors

The memristor, theorized as the fourth fundamental passive circuit element, has attracted intense interest for next-generation memory and neuromorphic computing. Gel-based memristors exploit ionic migration within hydrated polymer matrices to produce history-dependent conductance, offering mechanical flexibility, biocompatibility, and simple solution processing. Although magnetically assisted switching via the Lorentz force remains conceptually appealing, prior demonstrations required lithographically patterned electrodes and purified ionic liquids, which precluded low-cost, informal experimentation. The ORLOK (Organic Response-Linked Output Key) project addressed this limitation by realizing a volatile gel-electrolyte memristor fabricated entirely from commercial-grade materials. The active layer utilized a sodium-alginate gel doped with dissolved iron ions and sodium chloride, housed within a polymeric straw bounded by aluminum foil and carbon-felt electrodes. Hand-wound solenoid coils were used to generate perpendicular magnetic fields of approximately 5.3 mT (copper, 20 turns) and 1.7 mT (steel, 10 turns) to deflect mobile ionic trajectories. Current-voltage characterization using Arduino Due, the baseline device exhibited a quantifiable hysteresis loop with an integrated area of 0.000158 mA·V and a resistance coefficient of variation of 0.125, confirming genuine memristive behavior. Volatile memory testing achieved 99.07 +/- 0.2% read/write accuracy at 1.82 kHz, demonstrating memristive effects. Although the Lorentz force exerted on individual ions was negligible, collective perturbation from thermal and electrochemical factors within the mobile ionic population were sufficient to modulate conductivity. These results establish a proof-of-concept for neuromorphic, low-cost logic elements fabricated from accessible precursors.