A low overhead chemical measurement architecture with memristive sensors

Memristors, traditionally considered as non-volatile resistive memories for high-density applications, also exhibit excellent sensitivity to chemicals, making them suitable for chemical sensing with intrinsic memory capabilities. This paper introduces an innovative technique for directly measuring and digitising sensor readings, such as gas concentration, using the switching state of the device, which is influenced by the applied bias voltage or current in the presence of chemicals. When a sensor itself detects and measures a chemical property, its state changes, enabling the direct digitisation of the sensed information. The proposed memristive sensor employs a TiO 2 based memristor as both the sensing and digitising element, and is evaluated using SPICE simulations with hydrogen gas (H 2 ) at different concentrations. We present a calibration curve that establishes a reliable correlation between pulse counts and chemical concentration, highlighting the consistent relationship between switching behaviour and concentration levels. This method significantly reduces the reliance on separate analogue to digital converters (ADC), simplifying the sensor architecture in terms of power consumption and circuit complexity. Additionally, the inherent nonlinearity of the fabricated devices renders this digitisation method significantly nonlinear, which can provide an added layer of security to the measured information. This approach paves the way for compact, low-power chemical sensing nodes, making them suitable for future integrated environmental monitoring systems.