Piezoelectric MEMS Cooling Array for Mobile Processor Heat Dissipation

Solution Overview

Problem

Current cooling solutions for mobile devices, such as smartphones and tablets, are inadequate in addressing the heat dissipation needs of high-performance processors, leading to throttling and reduced performance due to insufficient heat transfer and noise from electric fans.

Innovation Solution

A piezoelectric MEMS-based cooling system that utilizes an array of cooling elements and a controller to actively manage heat dissipation by vibrating piezoelectric cooling elements to drive fluid through orifices, enhancing heat transfer efficiency and reducing noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If electric fans are used for cooling, then heat dissipation is improved, but device size increases and noise increases

Engineering Contradiction:

Improveheat dissipationVSAvoidnoise

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical fan system with a piezoelectric MEMS-based acoustic wave generation system. Instead of using rotating blades to move air, the invention uses piezoelectric actuators to generate acoustic waves that drive fluid flow through microchannels, eliminating mechanical moving parts and associated noise while maintaining cooling effectiveness

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The cooling system is divided into multiple independent piezoelectric MEMS elements arranged in an array. Each element can be independently controlled to generate acoustic waves at specific frequencies and amplitudes, allowing for precise control of fluid flow patterns and heat dissipation while keeping individual component sizes small

Inventive Principle:

Principle #1Segmentation

2Temperature

If electric fans are used for cooling, then heat dissipation is improved, but device size increases

Engineering Contradiction:

Improveheat dissipationVSAvoiddevice size

Core Design Contradiction:

TemperatureVSVolume of moving object

Solution Approach 1:

The cooling system is divided into multiple independent piezoelectric MEMS elements arranged in an array. Each element can be independently controlled to generate acoustic waves at specific frequencies and amplitudes, allowing for precise control of fluid flow patterns and heat dissipation while keeping individual component sizes small

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses acoustic waves (a form of pneumatic energy) to drive fluid flow through microchannels instead of using mechanical fans. The piezoelectric MEMS elements generate pressure waves that move the cooling fluid through the system, enabling compact design without large mechanical components

Inventive Principle:

Principle #29Pneumatics and hydraulics

3Productivity

If processor clock speed is increased, then performance is improved, but heat generation increases

Engineering Contradiction:

Improveprocessor speedVSAvoidheat generation

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The piezoelectric MEMS cooling system operates continuously to maintain optimal temperature conditions for high-performance processing. The acoustic wave generation and fluid flow are sustained without interruption, ensuring constant heat removal that enables continuous high-clock-speed operation without throttling

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The system incorporates temperature sensing and control logic that monitors thermal conditions and adjusts the intensity and frequency of acoustic wave generation accordingly. This feedback mechanism ensures optimal cooling performance matches the actual heat generation level, maintaining temperatures within safe operating ranges for high-speed processing

Inventive Principle:

Principle #23Feedback

4Temperature

If throttling is applied to reduce heat, then heat generation is reduced, but processor speed decreases

Engineering Contradiction:

Improveheat generationVSAvoidprocessor speed

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The piezoelectric MEMS cooling system operates continuously to maintain optimal temperature conditions for high-performance processing. The acoustic wave generation and fluid flow are sustained without interruption, ensuring constant heat removal that enables continuous high-clock-speed operation without throttling

Inventive Principle:

Principle #20Continuity of useful 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

The piezoelectric MEMS-based cooling system effectively increases heat transfer rates, allowing devices to operate at higher speeds for longer periods without throttling, while being quiet and power-efficient, suitable for use in mobile devices with limited space.

Implementation Method 1

The cooling element includes a piezoelectric structure and is configured to vibrate when actuated

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The cooling element is actuated to vibrate... the fluid moves through the orifices... allowing the fluid to move closer to and further from the heat-generating structure... enhancing heat transfer efficiency

Methodology Applied

Scientific EffectVibrational heat transfer: Vibration

Data Source

PatentUS11784109B2Method and system for driving piezoelectric MEMS-based active cooling devices

Publication Date: 2023.10.10 FRORE SYSTEMS INC

AI summary

A cooling system and method for using the cooling system are described. The cooling system includes an array of cooling elements and a controller. The array of cooling elements corresponds to regions of the heat-generating structure where heat is generated in response to operation of the semiconductor. The controller is configured to activate portions of the array of cooling elements based on a determination that operation of the heat-generating structure is likely to generate heat in a given region of the heat-generating structure.