Heat Flow Switching Element Using Electric Field Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional heat flow switching technologies face challenges such as reproducibility issues, mechanical deformation, and instability in thermal conduction due to physical thermal contact or chemical reactions, and lack sufficient thermal responsiveness and conductivity changes.
Innovation Solution
A heat flow switching element comprising an N-type semiconductor layer, an insulator layer, and a P-type semiconductor layer, where external voltage induces electric charges at interfaces, allowing for large changes in thermal conductivity and high thermal responsiveness without chemical reactions or self-heating, achieved through the use of thin film semiconductor layers and a dielectric insulator layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If physical thermal contact due to thermal expansion is used to change thermal conductivity, then thermal switching function is achieved, but reproducibility cannot be obtained and plastic deformation occurs due to mechanical contact pressure
Solution Approach 1:
The patent replaces the mechanical contact-based thermal switching mechanism with an electric field-based mechanism. Instead of using thermal expansion to create physical contact between materials, the invention applies an external electric field to induce electric charges at material interfaces, which then modulate thermal conductivity through charge-carrier-mediated heat transport. This substitution eliminates mechanical contact pressure and associated plastic deformation while achieving reliable, reversible thermal switching.
Solution Approach 2:
The patent changes the controlling parameter from mechanical contact pressure to electric field strength. By applying an external electric field, the system modulates the density of electric charges at interfaces between materials with different Seebeck coefficients, thereby controlling thermal conductivity. This parameter change enables precise, reproducible thermal switching without the mechanical degradation issues inherent in contact-based systems.
2Reliability
If chemical reaction mechanism is used to change thermal conduction, then thermal conductivity can be changed, but thermal responsiveness is poor and thermal conduction is unstable
Solution Approach 1:
The patent substitutes chemical reaction mechanisms with physical electric field effects. Instead of relying on slow chemical reactions to alter thermal conductivity, the invention uses an external electric field to induce electric charges at material interfaces. This physical mechanism responds instantaneously to field application and removal, achieving both high thermal responsiveness and stable, reversible thermal conduction control without chemical changes.
3Speed
If electric field is applied to generate thermal conductive electric charge at material interface, then thermal responsiveness is improved, but amount of generated electric charge is small resulting in limited thermal conductivity change
Solution Approach 1:
The patent employs a composite structure consisting of materials with different Seebeck coefficients (such as n-type and p-type thermoelectric materials) interfaced with a dielectric layer. This composite configuration enables the accumulation of electric charges at multiple interfaces when an external electric field is applied. The synergistic interaction between materials with contrasting Seebeck coefficients amplifies the total charge generation, producing sufficient thermal conductivity change while maintaining rapid thermal responsiveness.
Solution Approach 2:
The patent creates localized regions of high electric charge density at the interfaces between materials with different Seebeck coefficients. By positioning these high-charge-density regions precisely at the material interfaces where the electric field induces charge separation, the system maximizes the thermal conductivity modulation effect. This localized charge accumulation achieves large thermal conductivity changes without requiring uniformly high charge density throughout the entire structure, thereby maintaining fast response times.
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 solution enables active control of heat flow with significant thermal conductivity changes and high responsiveness, reducing contact thermal resistance and avoiding self-heating, while minimizing unnecessary thickness and manufacturing costs.
Implementation Method 1
when an external voltage is applied to an N-side electrode and a P-side electrode, electric charges are induced mainly at interfaces between the P-type semiconductor layer and the insulator layer, and at interfaces between the N-type semiconductor layer and the insulator layer
Implementation Method 2
a thermal conductivity is changed by the electric charges transferring heat
Implementation Method 3
an insulator layer which is laminated on the N-type semiconductor layer
Data Source
AI summary
Provided is a heat flow switching element which has a larger change in a thermal conductivity and has excellent thermal responsiveness. The heat flow switching element includes an N-type semiconductor layer, an insulator layer laminated on the N-type semiconductor layer, a P-type semiconductor layer laminated on the insulator layer, an N-side electrode connected to the N-type semiconductor layer, and a P-side electrode connected to the P-type semiconductor layer. In particular, the insulator layer is formed of a dielectric. Also, a plurality of N-type semiconductor layers and P-type semiconductor layers are laminated alternately with the insulator layer interposed therebetween.