The tolerance/resistance of the electronic devices to extremely harsh environments is of supreme interest. Surface effects and chemical corrosion adversely affect stability and operation uniformity of metal oxide resistive memories. To achieve the surrounding-independent behavior, the surface modification is introduced into the ZnO memristors via incorporating fluorine to replace the oxygen sites. F-Zn bonds is formed to prevent oxygen chemisorption and ZnO dissolution upon corrosive atmospheric exposure, which effectively improves switching characteristics against harmful surroundings. In addition, the fluorine doping stabilizes the cycling endurance and narrows the distribution of switching parameters. The outcomes provide valuable insights for future nonvolatile memory developments in harsh electronics.

Metal oxides suffering from oxygen molecule chemisorption display environment-dependent metastability, leading to unstable resistive memory characteristics and performance degradation. To obtain ambient-independent characteristics, we introduced nitrogen into ZnO resistive memory devices, compensating for the native defects and suppressing oxygen chemisorption, giving rise to a significant improvement in switching behavior without undesired surface effects. Moreover, by thermal activation of the nitrogen doping via annealing, an increased yield ratio from 50% to 82%, a reduced current compliance from 15 mA to 5 mA, and more stable cycling endurance are obtained. Our findings give physical insight into designing resistive memory devices.

A fully transparent resistive memory (TRRAM) based on Hafnium oxide (HfO2) with excellent transparency, resistive switching capability, and environmental stability is demonstrated. The retention time measured at 85 °C is over 3 × 104 sec, and no significant degradation is observed in 130 cycling test. Compared with ZnO TRRAM, HfO2 TRRAM shows reliable performance under harsh conditions, such as high oxygen partial pressure, high moisture (relative humidity = 90% at 85 °C), corrosive agent exposure, and proton irradiation. Moreover, HfO2 TRRAM fabricated in cross-bar array structures manifests the feasibility of future high density memory applications. These findings not only pave the way for future TRRAM design, but also demonstrate the promising applicability of HfO2 TRRAM for harsh environments.

We report the first paper-based nonvolatile memory device by means of an all-printing approach using a sequence of inkjet and screen printing techniques to fabricate a resistive random access memory on paper. The printed paper-based memory devices (PPMDs) can be labeled on electronics or living objects for multi-functional, wearable, on-skin, and biocompatible applications. The PPMDs would be a key electronic component to fully activate a paper-based circuit and can be directly implemented in medical biosensors, multi-functional devices, and self-powered systems.