Mobile Cooling Cells Using Vibration-Driven Fluid Spreading

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing cooling solutions for computing devices, such as smartphones and laptops, struggle to effectively manage heat, leading to hot spots and reduced performance, especially as devices generate more heat due to increased computing power.

Innovation Solution

The implementation of an active cooling system in mobile devices that utilizes vibrational motion to drive a fluid towards a heat-generating structure, achieving a high coefficient of thermal spreading (CTS) to efficiently dissipate heat.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If active cooling devices such as fans are used to drive air through computing devices, then heat dissipation is improved, but device size and complexity increase

Engineering Contradiction:

Improveheat dissipationVSAvoiddevice size

Core Design Contradiction:

TemperatureVSVolume of moving object

Solution Approach 1:

The patent replaces mechanical fans with a piezoelectric actuator that generates ultrasonic vibrations. This mechanical substitution eliminates the need for rotating blades and complex motor assemblies, dramatically reducing device volume while maintaining effective heat dissipation through vibration-induced fluid flow.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs ultrasonic mechanical vibrations generated by a piezoelectric actuator to drive fluid flow for cooling. The high-frequency vibrations create acoustic streaming effects that move cooling fluid through the device, providing passive cooling without mechanical moving parts.

Inventive Principle:

Principle #18Mechanical vibration

2Volume of moving object

If passive cooling devices such as heat spreaders are used in mobile devices, then device portability is improved, but cooling effectiveness deteriorates

Engineering Contradiction:

Improvedevice portabilityVSAvoidcooling effectiveness

Core Design Contradiction:

Volume of moving objectVSTemperature

Solution Approach 1:

The patent enhances passive heat spreaders by incorporating ultrasonic vibration through a piezoelectric actuator. The vibrations create micro-convection currents in the cooling fluid and increase thermal conduction at material interfaces, significantly improving cooling effectiveness while maintaining the compact form factor required for mobile devices.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent changes the physical state and flow characteristics of the cooling fluid through ultrasonic vibration. The high-frequency vibrations modify fluid density, viscosity, and flow velocity, transforming the cooling mechanism from purely conductive to a combination of conduction, convection, and acoustic streaming effects.

Inventive Principle:

Principle #35Parameter changes

3Temperature

If cooling solutions are added to manage heat, then temperature control is improved, but power consumption increases

Engineering Contradiction:

Improvetemperature controlVSAvoidpower consumption

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent uses ultrasonic vibrations at frequencies where piezoelectric actuators operate with high efficiency. The resonant frequency operation maximizes cooling effect per unit of electrical energy consumed, and the absence of mechanical friction and motor losses significantly reduces overall power consumption compared to traditional fan-based systems.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The piezoelectric actuator can be directly driven by the device's existing processor power management circuits, allowing the cooling system to self-regulate based on processor thermal output without requiring separate high-power control electronics. The actuator responds automatically to thermal conditions, providing adaptive cooling with minimal additional power overhead.

Inventive Principle:

Principle #25Self-service

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

This solution effectively reduces hot spots and improves thermal management, allowing mobile devices to maintain performance while minimizing user discomfort from excessive heat.

Implementation Method 1

a piezoelectric actuator configured to vibrate at a resonant frequency

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a housing and active cooling cells... configured to vibrate at a resonant frequency

Methodology Applied

Scientific EffectAcoustic wave generation: Acoustics

Implementation Method 3

improving heat transfer and reducing localized heating

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

drive a fluid toward a heat-generating structure... impinging the fluid at high speeds

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentUS12294668B2Mobile device having a high coefficient of thermal spreading

Publication Date: 2025.05.06 FRORE SYSTEMS INC

AI summary

A mobile device, such as a mobile phone, including a housing and active cooling cells is described. The active cooling cells are in the housing. The cooling cells utilize vibrational motion to drive a fluid such that the mobile phone has a coefficient of thermal spreading (CTS) greater than 0.5 for a steady-state power generated by the mobile phone of at least five watts.