Conductivity modulation in sodium caseinate biopolymer based resistive switching write-once-read-many times (WORM) memory device

Conductivity modulations in resistive random access memory (RRAM) devices are currently being extensively investigated for neuromorphic applications. In this work, a detailed investigation of the conductivity modulation in a bio-material-based resistive-switching write-once-read-many times (WORM) memory device is reported for the first time. Sodium caseinate (NaCas) biopolymer, extracted from the bovine milk, is used as the active layer for the WORM device. Our investigations reveal that conductance modulation can be achieved in Ag/NaCas/ITO device structure that exhibits WORM characteristics. It is also demonstrated that the NaCas-based WORM device is capable of exhibiting synaptic emulations like potentiation-depression, short-term-memory to long-term-memory and paired-pulse-facilitation, similar to that reported for the bipolar resistive switching and threshold switching memory devices. Such conductivity modulation in the WORM device may be attributed to the reversible partial alignment of casein micelles present in the active layer.