Boolean and Elementary Algebra with a Roll‐To‐Roll Printed Electrochemical Memristor (Adv. Mater. Technol. 5/2022)

Abstract

Information Storage and Processing A non‐volatile, conjugated polymeric electrochemical memristor is developed in article number 2101108 by Stephen H. Foulger and colleagues, that combines both information storage and processing. The three‐terminal device was fabricated by means of gravure roll‐to‐roll printing on a flexible substrate with a water‐soluble, self‐doped conjugated polymer and could perform both elementary algebra and Boolean logic‐based operations through very low power programming pulses.

Cascaded Logic Gates with Printed Electrochemical Memristors

“…The response of i post is further used to calculate the conductivity (G) of the post‐synaptic terminal ( i post = V post x G) and is analogous with the synaptic weight of a neuron. [ 12 ] A 1 MΩ resistor is used in series with the pre‐synaptic input to limit the device′s driving force ( i pre ). This resistor also aids in adequately disconnecting the two terminals by slowing down the electrochemical draining process.…”

“…This can be further optimized by either modifying the electrochemical films with additives, [ 4 ] tuning the material properties by adding an electro‐active species off the DTP backbone, [ 7,29 ] or adjusting the pre‐synaptic input parameters. [ 12 ]…”

“…This in situ technique utilizes an iron‐based salt oxidant‐coated surface to polymerize the desired monomer through a simple two‐step process of (1) depositing the oxidant over the desired substrate and then (2) exposing the coated substrate to a monomer vapor. [ 19 ] The VPP technique can be combined with screen printing to create devices with complex geometries over rigid, [ 19 ] flexible, [ 24 ] or non‐conformal [ 25 ] substrates with the added virtue of ease of scalability and high resolution. Where ECMs lack the ability to be solution processable due to their polymer‐form insolubility, VPP appears the only alternative to fabricating semiconducting films.…”

“…While common ECMs have been widely studied for their memristive properties, [ 4,8,12 ] a redox‐active conjugated polymer based on the heterocyclic dithienopyrrole (DTP) moiety has yet to be reported as a three‐terminal synaptic emulator. Recently, a two‐terminal device employed a polyDTP derivative with a carbazole moiety attached to the DTP backbone.…”

Temperature‐triggered oxidative polymerization for high conductive poly(3,4‐ethylenedioxythiophene) sheets at millimeter scale

“…To overcome these issues, there proposed two ways to improve hydrophilicity or lipophilicity of PEDOT. One is introducing additional functional groups such as alkyl chains 10,11 and sulfonates, 12,13 and the other is grafting PEDOT chains onto auxiliary substances 14 or soluble polymers 15 . A significant advance for the commercial application of PEDOT‐based conductive materials is the PEDOT:PSS emulsions 16 developed by the German company Bayer, which uses polystyrene sulfonate (PSS) as auxiliary polymer.…”