Transient and Biocompatible Resistive Switching Memory Based on Electrochemically-Deposited Zinc Oxide

"Transient" resistive random access memory (RRAM) has attracted tremendous research interests in recent years, due to its biodegradable characteristics and data storage capability. Zinc oxide (ZnO) has been widely used as the biodegradable and biocompatible material. However, research on ZnO based-RRAM shows undesired performance due to masses of intrinsic defects and low crystallinity in ZnO films when deposited using sputtering and so on. In this work, excellent crystallinity and oxygen vacancy-poor electrochemically-deposited zinc oxide (ED-ZnO) films are utilized as the active layer for fabricating transient resistive memory device with a structure of Ag/ED-ZnO/W. This ED-ZnO RRAM device exhibits uniform switching voltage, stable retention time (over 10(4) s) at 37 degrees C, and outstanding endurance up to 2500 cycles without obvious degradation. Additionally, a fully degradable RRAM device is fabricated by water-assisted transfer printing method and it can be dissolved completely after immersed in phosphate buffered saline solution without encapsulation layer after 60 min. The cell toxicity test demonstrates the biocompatibility of the dissolved memory device. These results suggest that the ED-ZnO based transient RRAM has a significant potential for data storage applications in transient electric system and implantable biomedical device.