Fully degradable biomimetic synaptic devices based on a W/MgO/ZnO/Mo memristor on a silk protein substrate show remarkable information storage and synaptic characteristics.

In this letter, dissolvable and biodegradable resistive switching devices with cell structure of Mg/MgO/Mg were demonstrated. Electrical tests demonstrated good memory characteristics for nonvolatile application. The dissolution rate of Mg and MgO are characterized in deionized (DI) water and in phosphate-buffered saline (PBS) solution, with clear difference, 0.36 nm/s, 1.25 nm/s, 0.057 nm/s and 0.13 nm/s, respectively. The Mg/MgO/Mg devices on silk fibroin substrates are able to be completely dissolved as fast as 30 minutes while immersed in DI water. The Mg/MgO/Mg devices have excellent prospects for applications in transient electronics, secure memory systems, and implantable medical therapy devices.Index Terms-resistive switching memory, magnesium oxide, transient electronics.

Transient memristors are prospective candidates for both secure memory systems and biointegrated electronics, which are capable to physically disappear at a programmed time with a triggered operation. However, the sneak current issue has been a considerable obstacle to achieve high-density transient crossbar array of memristors. To solve this problem, it is necessary to develop a transient switch device to turn the memory device on and off controllably. Here, a dissolvable and flexible threshold switching (TS) device with a vertically crossed structure is introduced, which exhibits a high selectivity of 10 , steep turn-on slope of <8 mV dec , and fast ON/OFF switch speed within 50/25 ns. Triggered failure could be achieved after soaking the device in deionized water for 8 min at room temperature. Furthermore, a water-assisted transfer printing method is used to fabricate flexible and transient TS device arrays for bioresorbable systems, in which none of any significant degradation is observed under a bending radius of 2 mm. Integrating the selector with a transient memristor is capable of 10 Gb memory implementation, indicating that the transient TS device could provide great opportunities to achieve highly integrated transient memory arrays.

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