Laminated Graphitic Heat Spreaders for Flexible Electronics
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Solution Overview
Problem
Conventional graphene-based thermal films lack the ability to withstand repeated bending deformations without significant degradation in thermal conductivity and structural integrity, making them unsuitable for flexible electronic devices that require high thermal management capabilities.
Innovation Solution
A laminated graphitic layer is developed, comprising graphitic or graphene films with a conducting polymer network adhesive, which provides high thermal and electrical conductivity while maintaining elasticity, allowing the film to withstand repeated bending cycles without significant thermal conductivity loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional graphene-based thermal films are used to achieve high thermal conductivity, then thermal management performance is improved, but the films cannot withstand repeated bending deformations without significant degradation in thermal conductivity and structural integrity
Solution Approach 1:
The patent uses a composite structure consisting of multiple graphene films laminated together with polymer adhesive layers in between. This composite material approach combines the high thermal conductivity of graphene with the flexibility and elasticity of polymers, enabling the thermal film to maintain both excellent thermal management performance and structural integrity under repeated bending deformations
Solution Approach 2:
The patent employs thin film technology by creating a flexible thermal management solution using laminated graphene films with thicknesses in the micrometer range. The flexible polymer adhesive layers between graphene sheets enable the entire structure to bend repeatedly without cracking, while maintaining thermal conductivity above 80% of original values after 10,000 bending cycles
2Length of stationary object
If graphene films are made thinner to reduce device thickness, then device miniaturization is achieved, but thermal conductivity and structural strength are compromised
Solution Approach 1:
The patent merges multiple thin graphene films with polymer adhesive layers to create a laminated composite structure. By combining several thin layers rather than using a single thick layer, the patent achieves high thermal conductivity through the stacked graphene sheets while the polymer layers provide flexibility and structural support, enabling thin overall thickness without compromising thermal performance
3Adaptability or versatility
If polymer adhesive is added to enable flexibility and repeated bending, then elasticity and bendability are improved, but thermal conductivity decreases due to the insulating nature of polymers
Solution Approach 1:
The patent applies local quality by using polymer adhesive only in thin intermediate layers between graphene sheets, rather than as the bulk material. The graphene films maintain high thermal conductivity in their planes, while the thin polymer layers provide flexibility without significantly blocking heat transfer. The polymer is strategically placed only where needed for bonding and flexibility, minimizing its thermal blocking effect
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
The laminated graphitic layer maintains over 80% of its original thermal conductivity after 10,000 bending cycles, offering a durable and efficient thermal management solution for flexible electronic devices.
Implementation Method 1
the graphitic or graphene film has a thermal conductivity of at least 200 W/mK
Implementation Method 2
an electrical conductivity no less than 3,000 S/cm
Implementation Method 3
the laminated graphitic layer has an in-plane thermal conductivity from 100 W/mK to 1,750 W/mK
Data Source
AI summary
Provided is a laminated graphitic layer as an elastic heat spreader, the layer comprising: (A) a plurality of graphitic or graphene films prepared from (i) graphitization of a polymer film or pitch film, (ii) aggregation or bonding of graphene sheets, or (iii) a combination of (i) and (ii), wherein the graphitic or graphene film has a thermal conductivity of at least 200 W/mK, an electrical conductivity no less than 3,000 S/cm, and a physical density from 1.5 to 2.25 g/cm3; and (B) a conducting polymer network adhesive that bonds together the graphitic or graphene films to form the laminated graphitic layer; wherein the conductive polymer network adhesive is in an amount from 0.001% to 30% by weight and wherein the laminated graphitic layer preferably has a fully recoverable tensile elastic strain from 1% to 50% and an in-plane thermal conductivity from 100 W/mK to 1,750 W/mK.