Natural-Casein-Based Biomemristor with Pinched Current-Voltage Characteristics.

A biomaterials based memristor is of great interest for applications in the environment and human friendly electronic systems. Although a pinched current-voltage (I-V) characteristic is a signature of Chua's memristor model, biomemristors generally exhibit nonpinched I-V response. This work reports the discovery of the pinched I-V characteristics of a natural casein-based biomemristor. Water-soluble sodium caseinate (NaCas), synthesized using natural casein that was extracted from edible animal milk, was used for the fabrication of a Al/NaCas/ITO biomemristor device. In addition to pinched I-V characteristics, the Al/NaCas/ITO device shows improved performance with a sufficiently large resistance window (∼20 times), longer retention time (∼10 s), and comparable cyclic endurance (>180 cycles), as compared with the reported biomemristors reported in the literature. A physical mechanism is proposed to explain the device characteristics.