Chemical Temperature Control Using Phase Change Heating

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Solution Overview

Problem

Current diagnostic technologies, such as PCR and isothermal nucleic acid amplification methods, require precise temperature control, which is often achieved using energetically expensive thermal cyclers, making them unsuitable for resource-limited settings like developing countries or remote surveillance.

Innovation Solution

A non-instrumented assay platform utilizing exothermic chemical reagent mixtures and phase change materials to maintain constant output temperatures, enabling reverse-transcription and isothermal nucleic acid signal amplification without the need for external equipment, through chemical heating and cooling elements that regulate temperature using exothermic or endothermic reactions and phase change materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If thermal cyclers are used for PCR temperature control, then temperature precision is improved, but device cost and energy consumption increase

Engineering Contradiction:
Improvetemperature precisionVSAvoiddevice cost
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs phase change materials (PCMs) that undergo phase transitions at specific temperatures to maintain constant temperature during PCR processes. The PCM absorbs or releases latent heat during phase change, providing passive temperature regulation without requiring active thermal cycler equipment, thereby reducing device cost while maintaining temperature precision.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The system uses self-regulating phase change materials that automatically maintain temperature without external control mechanisms. The PCM inherently regulates temperature through its phase transition properties, eliminating the need for complex thermal cycler systems with sensors, heaters, and controllers, thus reducing both device cost and complexity.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If thermal cyclers are used for PCR temperature control, then temperature precision is improved, but energy consumption increases

Engineering Contradiction:
Improvetemperature precisionVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

Phase change materials provide passive temperature regulation by absorbing or releasing latent heat during phase transitions. This eliminates the need for continuous energy input from thermal cyclers, significantly reducing energy consumption while maintaining the temperature precision required for PCR amplification.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The phase change materials self-regulate temperature without requiring external energy input or control systems. The inherent thermodynamic properties of the PCM provide automatic temperature stabilization, eliminating the energy-consuming heating and cooling cycles of traditional thermal cyclers.

Inventive Principle:
Principle #25Self-service

3Device complexity

If exothermic chemical reagent mixtures are used for heating, then device simplicity is improved, but temperature control precision deteriorates

Engineering Contradiction:
Improvedevice simplicityVSAvoidtemperature control precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent combines exothermic chemical reactions with phase change materials to achieve both simplicity and precision. The chemical reaction provides the heat source, while the PCM regulates the temperature through phase transitions, creating a self-regulating system that is simple in design but precise in temperature control.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The system uses composite heating elements that combine exothermic chemical reagents with phase change materials. This composite approach integrates the heat-generating capability of chemical reactions with the temperature-regulating properties of PCMs, achieving both device simplicity and temperature control precision simultaneously.

Inventive Principle:
Principle #40Composite materials

4Productivity

If isothermal amplification methods are used, then amplification efficiency is improved, but temperature control requirements become more stringent

Engineering Contradiction:
Improveamplification efficiencyVSAvoidtemperature control precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

Phase change materials provide inherent temperature stabilization at the specific transition temperature, which is ideal for isothermal amplification methods. The PCM maintains a constant temperature plateau during phase transition, ensuring the precise temperature control required for efficient isothermal nucleic acid amplification without requiring complex active control systems.

Inventive Principle:
Principle #36Phase transitions

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 allows for precise temperature control in diagnostic devices, facilitating sensitive and specific PCR assays and nucleic acid amplification in resource-constrained environments, eliminating the need for expensive thermal cyclers and enabling early detection of infectious diseases.

Implementation Method 1

The heating element comprises an exothermic chemical reagent mixture

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Implementation Method 2

a temperature regulating element comprising a phase change material that thermally cooperate to maintain a constant output temperature

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

generates heat as a consequence of crystallizing a supercooled liquid and generates heat at a constant temperature as a consequence of the liquid form of the exothermic phase change material being in equilibrium with the solid form

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 4

crystallizing a supercooled liquid

Methodology Applied
Scientific EffectSupercooling: Supercooling

Data Source

PatentEP2153295B1Chemical temperature control
Publication Date: 2014.11.05 PATH
  • EP2153295B1 patent drawingFigure 1
  • EP2153295B1 patent drawingFigure 2
  • EP2153295B1 patent drawingFigure 3

AI summary

Exothermic and/or endothermic chemical reactions in combination with phase change materials can produce output temperature(s) within strict tolerances without requiring expensive and complicated external equipment to generate and maintain an output temperature. Similarly, an exothermic phase change material, which generates heat as a consequence of crystallizing a supercooled liquid, can generate heat at a constant temperature, without requiring expensive and complicated external equipment, as a consequence of the liquid form of the exothermic phase change material being in equilibrium with the solid form of the exothermic phase change material. Numerous biological and chemical processes and/or diagnostic devices require a constant temperature or temperatures for set periods of time. An example completely non- instrumented diagnostic platform based on nucleic acid amplification is described, which is particularly suited for use in developing countries that may not have access to expensive and complicated external equipment.