Two-Dimensional Material Stress Control via Patterned Base Topography

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing two-dimensional materials' physical properties are not effectively controlled due to limitations in managing stress-induced changes in atomic spacing, which affects their energy band structure and other properties like conductivity and refractive index.

Innovation Solution

A device and method involving a base layer with a patterned surface and a two-dimensional structure layer that adapts to the topography, inducing stress-dependent changes in physical properties by conforming to the base layer's surface, utilizing materials like graphene or molybdenum disulfide, and employing techniques such as photolithography and CVD for layer formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If two-dimensional materials are subjected to stress to change atomic spacing and control physical properties, then the physical properties (conductivity, refractive index, etc.) can be adjusted, but the stress control and distribution become difficult to manage precisely

Engineering Contradiction:

Improvephysical property controlVSAvoidstress distribution control

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The base layer is designed with a patterned surface containing regions of different heights, creating localized areas with distinct mechanical properties. When the two-dimensional material is formed on this patterned surface, different regions experience different stress states (tensile or compressive) depending on their position relative to the height patterns, enabling spatially-resolved control of physical properties

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patterned surface incorporates curved or non-planar height variations rather than flat surfaces. This curvature creates controlled strain gradients in the overlying two-dimensional material, allowing precise modulation of atomic spacing and consequently the physical properties through geometric design of the base layer topography

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Reliability

If the two-dimensional material layer is made thinner to maintain two-dimensional characteristics, then the material exhibits stronger two-dimensional properties, but the material becomes more sensitive to stress-induced deformations

Engineering Contradiction:

Improvetwo-dimensional material propertiesVSAvoidstress sensitivity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

By varying the height parameters of the patterned base layer features, the stress state applied to the two-dimensional material can be precisely tuned. This allows optimization of the balance between maintaining thin-film two-dimensional characteristics and controlling stress-induced effects to achieve desired physical properties without excessive sensitivity

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If a patterned base layer is created to induce stress control, then physical property modulation is achieved, but the manufacturing process complexity increases

Engineering Contradiction:

Improvephysical property modulationVSAvoidmanufacturing process complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The base layer is pre-patterned with the desired height variations before the two-dimensional material is formed. This preliminary structuring of the substrate allows the subsequent two-dimensional material formation to proceed with automatic stress patterning, avoiding the need for complex post-processing or multi-step stress application procedures

Inventive Principle:

Principle #10Preliminary action

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 allows for controlled variations in physical properties such as conductivity, magnetic flux, and optical properties by managing lattice deformation and stress distribution, enhancing the material's performance in electronic and optical applications.

Implementation Method 1

When the lattice arrangement of a two-dimensional material is subjected to compressive stress or tensile stress, atomic spacing thereof changes. The change in atomic spacing leads to the change of energy band structure, and consequently gives rise to other physical properties, including an electric conductivity, a magnetic connectivity, an optical refractive index

Methodology Applied

Scientific EffectStress-induced lattice deformation: Deformation

Implementation Method 2

the two-dimensional structure layer extending on and in compliance with surface topography of the base layer... the change of the physical properties of the two-dimensional structure layer depends on topography-induced stress

Methodology Applied

Scientific EffectTopography-induced stress: Mechanical Force

Data Source

PatentUS11358868B2Device comprising physical properties controlled by microstructure and method of manufacturing the same

Publication Date: 2022.06.14 NAT CHENG KUNG UNIV

AI summary

The present invention relates to a device comprising physical properties controlled by a microstructure and a method of manufacturing the same. The present invention discloses a base layer having a patterned surface; and a two-dimensional structure layer formed on the patterned surface of the base layer, the two-dimensional structure layer extending on and in compliance to topography of the patterned surface of the base layer, such that change of physical properties of the two-dimensional structure layer conforms to the stress generated along the topography.