All-nanocellulose nonvolatile resistive memory

Single-use disposable nonvolatile memory devices hold promise for novel applications in internet of everything (IoE) technology by storing the health status of individual humans in daily life. However, conventional memory devices are not disposable because they are mostly composed of non-renewable, non-biodegradable and sometimes toxic materials, causing serious damage to ecological systems when they are released to the environment. Here, we demonstrate an environment-friendly, disposable nonvolatile memory device composed of 99.3 vol.% nanocellulose. Our memory device consists of a nanocellulose-based resistive-switching layer and a nanopaper substrate. The device exhibited nonvolatile resistive switching with the capability of multilevel storage and potential scalability down to the single nanofiber level (ca. 15 nm). The biodegradability of our memory device was confirmed by burying it in natural soil for 26 days. Environmentally friendly memory cells that use ‘nanopaper’ substrates instead of silicon have been produced by an international team. The rising use of networked devices in consumer packaging and biomedical implants has created a need for recyclable electronic materials. By manipulating nanoscale cellulose fibres into extremely flat, paper-like substrates, Takeshi Yanagida from Kyushu University in Japan and co-workers have produced a nonvolatile memory device that can be composted. The team's technique first turned wood chips into nanopaper through a spraying and casting routine. Then, coating opposite sides of the nanopaper with silver and indium tin oxide electrodes produced a see-through, resistive switching device capable of multilevel persistent memory storage. Following water-based treatments to remove the electrodes, the nanopaper substrates biodegraded completely after being buried in soil for 26 days. Conventional memory devices are not disposable as they are mostly composed of non-renewable, non-biodegradable and some toxic materials, causing a serious damage for ecological system when they are emitted to the environment. Here we demonstrate an environment-friendly, disposable nonvolatile memory device composed of 99.3 vol.% nanocellulose. Our device consists of a nanocellulose-based resistive-switching layer and nanopaper substrate. The device exhibited the nonvolatile resistive switching with the capability of multilevel storage and the potential scalability down to single nanofiber level. Furthermore, the biodegradability of our memory device was confirmed by burying it into the natural soil for 26 days.