Biodegradable and Flexible Resistive Memory for Transient Electronics

Physically transient electronics have attracted increasing attention recently due to their potential as the basis for building "green" electronics and biomedical devices. In the development of transient devices for biomedical applications, however, the dilemma between the strictly required biodegradability and device performance has brought great difficulties to the material selection. In this paper, we introduced silk fibroin as dielectric layer to fabricate biodegradable resistive memory devices. Comprising a W/silk fibroin/Mg sandwich structure, stable bipolar resistive switching behavior with good repeatability and device variability was obtained, surpassing most organic resistive memory and comparable to inorganic resistive memory. The carrier-transport evolution process was carefully examined to reveal the mechanism behind resistive switching. A switching model regarding the formation of metallic conductive filament was proposed by considering both the nature of silk fibroin dielectric layer and the key role of active metal electrode. Furthermore, the solubility test in phosphate-buffered saline indicates the device exhibiting physically transient behavior and good biodegradability. Good mechanical property and flexibility were also demonstrated through electrical testing under different bending conditions. These results suggest that our device is a promising memory element candidate for constructing transient electronic system, especially for biomedical applications.