The working mechanism involves symmetric polarization of the device and the output current, which is characterized by two distinct current responses. Under positive polarization, the current response is minimum and the polarization is noted as "blocked" polarization. In the other direction high current response is registered and the polarization is noted as "open" polarization (U < 0 V). The unidirectional current flow of the CAPode device is achieved by controlling the device reaction under "open" polarization and eliminating the reaction under blocked polarization. Under "open" polarization, high current response originated from cations (e.g., H⁺, Li⁺, Na⁺, K⁺, Mg⁺ 2 ) intercalated to the nanosized h-WO3, and the charge balance achieved by adsorption of counter ion to NC. In contrast, under "blocked" polarization, the anions are not able to intercalate to nanosized h-WO3 and the current is minimized. The G-Cap device operates with a potential shift concept to control the output capacity and current. The GE is utilized to fine control the reaction rate occurring in the WE (intercalation). Different biases are tested and optimized to reach the transistor-like performance.