Electronic memristors have greatly advanced artificial synapse research, but their reliance on electron transport, which differs intrinsically from the ion-mediated signaling and spatiotemporal dynamics of biological synapses. Here, we present wrinkle-based, geometry-tunable nanochannels integrated within a hybrid polydimethylsiloxane (PDMS)-OSTEMER chip as a simple, low-cost, and reproducible platform for ionic memory. Exploiting the modulus mismatch between PDMS and OSTEMER, nanoscale wrinkles were selectively preserved only within the designated bridge region, forming a controllable array of nanochannels that govern ionic transport. By tailoring the number and length of these nanochannels, ionic conduction and memory characteristics could be precisely modulated. The resulting wrinkle-based nanochannel array device (WNAD) exhibited pronounced memristive hysteresis and effectively emulated key synaptic plasticity behaviors, including short-term plasticity (STP), paired-pulse facilitation (PPF), and reproducible potentiation-depression cycles. Moreover, the WNAD reproduced cumulative reinforcement under repeated stimulation, demonstrating geometry-dependent memory consolidation analogous to biological conditioning. Collectively, this study established wrinkle-based nanochannels as a bioinspired nanofluidic platform for ionic memory, bridging confined ionic transport and neuromorphic functionality.