Ionic Devices With Membrane And Ion-Blocking Barriers

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Solution Overview

Problem

Ionic devices face challenges in achieving both fast switching and long retention times due to high ion mobility, which often results in poor non-volatile retention as they tend to relax quickly to a stable ion concentration profile.

Innovation Solution

The introduction of an 'ionic bottle' effect by doping the ionic conductor with impurities that create a mirror charge, repelling active ions and confining them within the device, enhancing stability and retention of ion concentration profiles between electrodes and an ion-permeable membrane.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If high ion mobility is used to achieve fast switching, then switching speed is improved, but retention time deteriorates due to quick relaxation to stable ion concentration profile

Engineering Contradiction:

Improveswitching speedVSAvoidretention time

Core Design Contradiction:

SpeedVSDuration of action of stationary object

Solution Approach 1:

The ionic conductor layer is divided into multiple segments by introducing ion-blocking barriers at strategic positions. These barriers segment the ion migration paths, creating confined regions where ions can be stably retained. The segmentation allows fast switching within each segment while preventing overall relaxation, thus resolving the contradiction between switching speed and retention time.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Ion-blocking barriers are introduced as intermediary elements between the electrodes and the ionic conductor. These barriers act as mediators that selectively block ion migration in the retention state while allowing controlled ion movement during switching. The barriers enable the system to achieve both fast switching (when voltage is applied) and long retention (when voltage is removed) by mediating ion transport behavior.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If ion concentration is allowed to relax to stable profile, then thermodynamic equilibrium is achieved, but device state changes and information is lost

Engineering Contradiction:

Improvethermodynamic equilibriumVSAvoiddevice state

Core Design Contradiction:

Stability of the object's compositionVSLoss of information

Solution Approach 1:

Ion-blocking barriers are strategically positioned to preemptively prevent ion migration toward unstable regions before relaxation can occur. The barriers create artificial potential wells that trap ions in metastable states, applying preliminary anti-action against the natural relaxation tendency. This allows the device to maintain non-equilibrium states that encode information, preventing information loss while achieving compositional stability within confined regions.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The system changes the energy landscape parameters by introducing ion-blocking barriers that create localized potential minima. These parameter changes transform the single stable equilibrium into multiple metastable states, allowing the device to maintain information-encoded ion distributions. The barriers modify the thermodynamic parameters locally, enabling stable retention of non-equilibrium ion profiles.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly improves the stability and retention of ion states, allowing for fast switching and long retention times, with the ion concentration profiles maintained even when no external voltage is applied, achieving a high retention to switching speed ratio.

Implementation Method 1

The source material is the initial source of the mobile ions. Application of a voltage having the proper polarity and sufficient magnitude between electrodes 110 and 130 can then drive, an ion current that moves ions 125 from layer 122 into layer 124

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

Application of a voltage having the proper polarity and sufficient magnitude between electrodes 110 and 130 can then drive, an ion current that moves ions 125 from layer 122 into layer 124

Methodology Applied

Scientific EffectIon drift: Electrophoresis

Implementation Method 3

doping the ionic conductor with impurities that create a mirror charge, repelling active ions and confining them within the device

Methodology Applied

Scientific EffectElectrostatic repulsion: Ion Repulsion/Attraction

Data Source

PatentUS8705265B2Ionic devices containing a membrane between layers

Publication Date: 2014.04.22 HEWLETT PACKARD ENTERPRISE DEV LP

AI summary

A device contains a first layer, a second layer; and a membrane between the first and second layers. Mobile ions are in at least one of the first and second layers, and the membrane is permeable to the ions. Interfaces of the conductive membrane with the first layer and the second layer are such that charge of a polarity of the ions collects at the interfaces.