Piezoelectric MEMS Cooling for Mobile Processor Heat Dissipation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

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 fans, while passive solutions like heat spreaders and heat pipes are insufficient for future heat management.

Innovation Solution

A piezoelectric MEMS-based active cooling system that uses a vibrational motion to direct fluid perpendicular to the surface of heat-generating structures, enhancing heat transfer by thinning the boundary layer and increasing fluid speed, thus efficiently dissipating heat without the noise associated with traditional fans.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

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

Engineering Contradiction:

Improveheat dissipationVSAvoidnoise

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent uses a piezoelectric element to generate ultrasonic vibrations that agitate the cooling fluid, creating acoustic streaming effects that enhance heat transfer from the processor surface without requiring mechanical fans, thereby eliminating fan noise while improving cooling efficiency

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent replaces the mechanical fan-based cooling system with a piezoelectric ultrasonic vibration system that uses acoustic fields to drive fluid circulation and heat transfer, substituting mechanical motion with acoustic field effects to achieve noise-free operation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If processors run at high clock speeds, then performance is improved, but heat generation increases causing throttling

Engineering Contradiction:

Improveprocessor speedVSAvoidheat generation

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The patent applies continuous ultrasonic vibrations to the cooling fluid, maintaining constant acoustic streaming and turbulence that continuously remove heat from the processor surface, enabling sustained high-performance operation without thermal throttling

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent changes the physical state and flow characteristics of the cooling fluid through ultrasonic agitation, creating micro-turbulence and enhancing convective heat transfer parameters to increase heat removal capacity and allow higher processor speeds

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If passive cooling solutions like heat spreaders are used, then device complexity is reduced, but heat transfer effectiveness is insufficient

Engineering Contradiction:

Improvecooling system simplicityVSAvoidheat transfer effectiveness

Core Design Contradiction:

Device complexityVSTemperature

Solution Approach 1:

The patent employs periodic ultrasonic vibrations at specific frequencies to create oscillating pressure waves in the cooling fluid, generating periodic turbulence and acoustic streaming that significantly enhance heat transfer effectiveness beyond passive conduction methods

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent uses acoustic pressure waves generated by piezoelectric ultrasonic vibrations to drive fluid circulation and enhance convective heat transfer, utilizing acoustic-hydraulic effects to improve cooling performance while maintaining system simplicity

Inventive Principle:

Principle #29Pneumatics and hydraulics

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 cooling system effectively maintains high-performance operation by efficiently dissipating heat, allowing processors to run at higher speeds for longer periods without throttling, while being quiet and power-efficient, suitable for small form factors in mobile devices.

Implementation Method 1

a piezoelectric element coupled to the processor and configured to vibrate at an ultrasonic frequency to generate acoustic waves in the cooling fluid

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

the acoustic waves enhance movement of the cooling fluid across a surface of the processor and enhance removal of heat from the processor

Methodology Applied

Scientific EffectAcoustic streaming: Ultrasound

Data Source

PatentUS11735496B2Piezoelectric MEMS-based active cooling for heat dissipation in compute devices

Publication Date: 2023.08.22 FRORE SYSTEMS INC

AI summary

An active cooling system and method for using the active cooling system are described. The active cooling system includes a cooling element having a first side and a second side. The first side of the cooling element is distal to a heat-generating structure and in communication with a fluid. The second side of the cooling element is proximal to the heat-generating structure. The cooling element is configured to direct the fluid using a vibrational motion from the first side of the cooling element to the second side such that the fluid moves in a direction that is incident on a surface of the heat-generating structure at a substantially perpendicular angle and then is deflected to move along the surface of the heat-generating structure to extract heat from the heat-generating structure.