title: Optical Input/Electrical Output Memory Elements based on a Liquid Crystalline Azobenzene Polymer.
abstract: Responsive polymer materials can change their properties when subjected to external stimuli. In this work, thin films of thermotropic poly(metha)acrylate/azobenzene polymers are explored as active layer in light-programmable, electrically readable memories. The memory effect is based on the reversible modifications of the film morphology induced by the photoisomerization of azobenzene mesogenic groups. When the film is in the liquid crystalline phase, the trans → cis isomerization induces a major surface reorganization on the mesoscopic scale that is characterized by a reduction in the effective thickness of the film. The film conductivity is measured in vertical two-terminal devices in which the polymer is sandwiched between a Au contact and a liquid compliant E-GaIn drop. We demonstrate that the trans → cis isomerization is accompanied by a reversible 100-fold change in the film conductance. In this way, the device can be set in a high- or low-resistance state by light irradiation at different wavelengths. This result paves the way toward the potential use of poly(metha)acrylate/azobenzene polymer films as active layer for optical input/electrical output memory elements.
authors.affiliation: ISIS & icFRC, Université de Strasbourg & CNRS , 8 allée Gaspard Monge, 67000 Strasbourg, France.|Scriba Nanotecnologie , via di Corticella 183/8, 40128 Bologna, Italy.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mosciatti
authors.affiliation: ISIS & icFRC, Université de Strasbourg & CNRS , 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Sara
authors.initials: S
authors.lastname: Bonacchi
authors.affiliation: ISIS & icFRC, Université de Strasbourg & CNRS , 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Marco
authors.initials: M
authors.lastname: Gobbi
authors.affiliation: ISIS & icFRC, Université de Strasbourg & CNRS , 8 allée Gaspard Monge, 67000 Strasbourg, France.|Istituto per la Microelettronica e Microsistemi (IMM)-CNR , via Piero Gobetti 101, 40129 Bologna, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Ferlauto
authors.affiliation: Istituto per la Microelettronica e Microsistemi (IMM)-CNR , via Piero Gobetti 101, 40129 Bologna, Italy.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Liscio
authors.affiliation: Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna , Viale Risorgimento 4, 40136 Bologna, Italy.
authors.forename: Loris
authors.initials: L
authors.lastname: Giorgini
authors.affiliation: ISIS & icFRC, Université de Strasbourg & CNRS , 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Orgiu
authors.affiliation: ISIS & icFRC, Université de Strasbourg & CNRS , 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Paolo
authors.initials: P
authors.lastname: Samorì
keywords: azobenzene; memory device; multifunctional device; photochromic polymers; polymeric liquid crystals