Nanotube Fabric Joule Heating Elements for Phase Change Memory
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for efficient, small-scale heat transfer elements that can be easily fabricated and integrated into electronic devices, particularly for applications in the semiconductor industry, where rapid and precise control of heat emission is required for switching states of materials in memory devices.
Innovation Solution
The use of nanotube fabrics as Joule heating elements, which can be electrically stimulated to induce high temperatures with minimal current, allowing for precise control of heat emission and phase changes in materials, such as chalcogenide materials, through their integration into memory systems and other electronic applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If individual nanotubes are used for heat emission, then high heat conductivity and current density are achieved, but difficulties arise in growing them with suitably controlled orientation, length, and other properties
Solution Approach 1:
The patent segments the nanotube structure into arrays of individual nanotubes that are grown in a controlled manner. Each nanotube acts as an independent heating element, allowing the system to maintain the high heat conductivity and current density of individual nanotubes while enabling control over orientation and length through array configuration and growth parameters
Solution Approach 2:
The patent applies local quality by creating regions with different nanotube densities, orientations, and lengths to optimize heat emission at specific locations. The nanotube arrays are positioned and configured to provide localized thermal control, with variations in structure tailored to specific functional requirements of different device regions
2Volume of moving object
If smaller-scale heating elements are used, then integration into electronic devices is improved, but fabrication complexity and integration difficulty increase
Solution Approach 1:
The patent creates nanotube-based heating elements that can be integrated into existing semiconductor fabrication processes, making them universally applicable to various electronic devices. The nanotube arrays serve multiple functions including heating, current conduction, and potential sensing, reducing the need for separate components and simplifying integration
Solution Approach 2:
The patent replaces traditional mechanical or resistive heating elements with nanotube-based Joule heating elements that can be fabricated using vapor-phase growth processes. This substitution enables smaller-scale heating elements to be created through chemical vapor deposition or similar processes that are compatible with semiconductor manufacturing, avoiding complex mechanical assembly
3Speed
If rapid cycling of heating elements is implemented, then switching speed of material states is improved, but energy consumption and thermal management challenges increase
Solution Approach 1:
The patent implements periodic action through rapid cycling of the nanotube heating elements to switch material states. The nanotubes are activated in periodic pulses that are optimized to achieve phase changes or material state transitions at high speeds. The periodic heating allows for precise temporal control of thermal energy delivery, enabling fast switching while managing overall energy consumption through duty cycle optimization
Solution Approach 2:
The patent exploits phase transitions of materials (such as phase change materials transitioning between crystalline and amorphous states) to achieve rapid state switching. The nanotube heating elements provide the necessary thermal energy to induce these phase transitions, and the latent heat involved in the phase change allows for efficient energy utilization during the switching process
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
Nanotube fabrics enable rapid and efficient heat emission with small current inputs, allowing for temperature changes of several hundred Kelvin in short timescales, facilitating the development of compact, high-performance memory devices and other electronic applications with improved heat management.
Implementation Method 1
Nanotube fabrics enable rapid and efficient heat emission with small current inputs, allowing for temperature changes of several hundred Kelvin in short timescales
Data Source
AI summary
Methods and systems of using nanotube elements as joule heating elements for memories and other applications. Under one aspect, a method includes providing an electrical stimulus, regulated by a drive circuit, through a nanotube element in order to heat an adjacent article. Further, a detection circuit electrically gauges the state of the article. The article heated by the nanotube element is, in preferred embodiments, a phase changing material, hi memory applications, the invention may be used as a small-scale CRAM capable of employing small amounts of current to induce rapid, large temperature changes in a chalcogenide material. Under various embodiments of the disclosed invention, the nanotube element is composed of a non-woven nanotube fabric which is either suspended from supports and positioned adjacent to the phase change material or is disposed on a substrate and in direct contact with the phase change material. A plurality of designs using various geometric orientations of nanotube fabrics, phase change materials, and drive and detection circuitry is disclosed. Additionally, methods of fabricating nanotube heat emitters are disclosed.