Hydrogen‐Assisted Asymmetric and Nonlinear Memristor Array for Reconfigurable Olfactory Graph Networks

Memristor‐based olfactory systems have attracted significant interest. However, a multifunctional memristor array capable of sensing, memory, and computation has not been realized. This study develops a selector‐less crossbar array (CBA) composed of Pt/HfO 2 nanorods/TiN memristors, termed “chemo‐memristive” devices, that exhibits asymmetric current–voltage ( I–V ) characteristics under a hydrogen (H 2 ) atmosphere. H 2 exposure creates oxygen vacancies (V O ) in the nanogap, corresponding to the ruptured filament region. The V O ‐H complexes form shallow traps that enable trap‐assisted conduction under the TiN‐injection polarity, thereby switching the I–V response from symmetric to a polarity‐dependent, asymmetric one. This yields an H 2 ‑assisted intermediate‑resistance state and enables analog resistance tuning via NG widening. Hence, precise conductance modulation and cell‐selective readout were achieved by exploiting the forward‐reverse current asymmetry, as validated in selector‐free operation of a 3 × 3 CBA. Modified National Institute of Standards and Technology digit pattern‐recognition simulations demonstrate high inference accuracy (>94%) with highly linear and symmetrical conductance modulation, suitable for large‐scale arrays. The adjustable I–V properties allow an electrically reconfigurable olfactory network that can process H 2 flow patterns using high‐dimensional graph features. A single H 2 ‑assisted CBA integrates selective sensing, which reinforces intended paths, with analog in‑memory computation, enabling combined neuromorphic and electronic‑olfaction functionality.