Piezoelectric MEMS Virtual Valves for Compact Quiet Cooling

Solution Overview

Problem

Existing cooling solutions for computing devices, such as fans and passive heat spreaders, are inadequate for efficiently cooling both mobile and larger devices due to limitations in air flow speed and noise generation.

Innovation Solution

An active cooling system utilizing piezoelectric MEMS cooling elements with vents that create virtual valves, allowing for the modulation of fluid flow resistance through vibrational motion to efficiently direct fluid towards heat-generating structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If fans are used to drive air through computing devices, then cooling effectiveness is improved, but device size and noise increase

Engineering Contradiction:

Improvecooling effectivenessVSAvoidnoise

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent employs piezoelectric MEMS cooling elements that vibrate at ultrasonic frequencies to drive fluid flow through the computing device. This vibrational mechanism replaces traditional rotating fans, achieving effective cooling while eliminating fan noise and enabling compact device integration.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The invention substitutes the mechanical fan system with a piezoelectric-based fluid pumping system. The piezoelectric elements convert electrical energy directly into mechanical vibrations that pump fluid through channels, replacing the need for rotating mechanical components and eliminating associated noise.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Temperature

If fans are used to drive air through computing devices, then cooling effectiveness is improved, but device size increases

Engineering Contradiction:

Improvecooling effectivenessVSAvoiddevice size

Core Design Contradiction:

TemperatureVSVolume of moving object

Solution Approach 1:

The patent employs piezoelectric MEMS cooling elements that vibrate at ultrasonic frequencies to drive fluid flow through the computing device. This vibrational mechanism replaces traditional rotating fans, achieving effective cooling while eliminating fan noise and enabling compact device integration.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The invention substitutes the mechanical fan system with a piezoelectric-based fluid pumping system. The piezoelectric elements convert electrical energy directly into mechanical vibrations that pump fluid through channels, replacing the need for rotating mechanical components and eliminating associated noise.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Volume of moving object

If passive heat spreaders are used in computing devices, then device size is reduced, but cooling effectiveness decreases

Engineering Contradiction:

Improvedevice sizeVSAvoidcooling effectiveness

Core Design Contradiction:

Volume of moving objectVSTemperature

Solution Approach 1:

The invention substitutes the mechanical fan system with a piezoelectric-based fluid pumping system. The piezoelectric elements convert electrical energy directly into mechanical vibrations that pump fluid through channels, replacing the need for rotating mechanical components and eliminating associated noise.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes fluid dynamics principles by pumping liquid or gas through channels that contact heat-generating components. The piezoelectric elements create pressure variations that drive fluid flow, enabling active heat removal through convection and advection while maintaining compact device dimensions.

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 active cooling system effectively dissipates heat from heat-generating structures by impinging fluid at high speeds, thinning the boundary layer, and improving heat transfer, thereby enabling higher performance and longer operation times for computing devices without significant noise or power increase.

Implementation Method 1

An active cooling system may include a piezoelectric micro-electrical mechanical system (MEMS) cooling element

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The cooling element is actuated to vibrate to drive the fluid toward the heat-generating structure and to alternately open and close at least one virtual valve corresponding to the vent

Methodology Applied

Scientific EffectVibrational motion: Vibration

Implementation Method 3

impinging fluid at high speeds, thinning the boundary layer, and improving heat transfer

Methodology Applied

Scientific EffectBoundary layer thinning: Boundary Layer

Data Source

PatentUS20250075825A1Virtual valve in a MEMS-based cooling system

Publication Date: 2025.03.06 FRORE SYSTEMS INC

AI summary

An active cooling system is described. The active cooling system includes at least one cooling element that has a vent therein and is in communication with a fluid. The cooling element(s) are actuated to vibrate to drive the fluid toward a heat-generating structure and to alternately open and close at least one virtual valve corresponding to the vent. The virtual valve is open for a low flow resistance and closed for a high flow resistance. The vent remains physically open for the virtual valve being closed.