Keio University Develops Advanced Ammonia Gas Sensor Utilizing Tungsten Disulfide Memristors

Researchers at Keio University have successfully developed and demonstrated a novel horizontal gas sensor leveraging memristor technology and two-dimensional layered materials. The sensor integrates tungsten disulfide as the active channel material in a planar architecture, offering superior responsiveness due to the direct exposure of the conduction path to ambient gas molecules.

Using chemical vapor deposition, the research team synthesized approximately thirty-five micrometers of tungsten disulfide on a silicon substrate capped with a layer of silicon dioxide. Silver and platinum electrodes were fabricated at both ends of the channel to complete the device structure. The device demonstrated stable memristive operational behavior under applied voltages ranging from zero to eighty volts.

When exposed to ammonia gas at an operating voltage of fifty volts, the electrical current through the tungsten disulfide channel showed a distinct decrease, confirming its high sensitivity and effective sensing performance. Moving forward, the research team plans to investigate temperature dependency and selectivity toward other target gases to optimize the sensor for industrial and environmental monitoring applications.