Plasma Sterilization via Feed Pipe Reactive Species Transport

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Solution Overview

Problem

Existing plasma sterilization methods are unsuitable for industrial scale due to laborious procedures, cause damage to objects through thermal or electromagnetic shocks, use hazardous gases like ethylene oxide, and require complex and costly apparatus adjustments.

Innovation Solution

A method using a plasma generator device with electrodes in a feed pipe to produce reactive oxygen and nitrogen species in a dehumidified air environment, controlled by sensors and a control unit, allowing efficient sterilization without hazardous gases and adaptable to existing plants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If plasma is generated directly in the sterilization chamber, then sterilization effect is achieved, but thermal or electromagnetic shocks damage the objects

Engineering Contradiction:
Improvesterilization effectVSAvoidthermal or electromagnetic shocks
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a feed pipe as an intermediary component between the plasma generator and the sterilization chamber. The plasma is generated in the feed pipe and then transported through the pipe to the chamber, acting as a mediator that decouples the plasma generation zone from the objects to be sterilized, thereby preventing direct exposure to thermal or electromagnetic shocks while maintaining the sterilization effect.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If water vapor is introduced in the sterilization chamber, then plasma generation is facilitated, but corrosive phenomena occur on metal parts

Engineering Contradiction:
Improveplasma generation conditionsVSAvoidcorrosive phenomena
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes water vapor from the sterilization chamber environment by using a dehumidification system. This eliminates the harmful corrosive effect of water vapor on metal parts while still allowing plasma generation to occur, as the plasma is generated in the feed pipe using controlled gas composition without requiring high humidity in the chamber.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If ethylene oxide gas is used for sterilization, then sterilization effect is achieved, but toxic residues and flammability risks are created

Engineering Contradiction:
Improvesterilization effectVSAvoidtoxic residues and flammability
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameter of the sterilizing agent by using a plasma-based system that generates reactive species in situ, replacing ethylene oxide gas. This parameter change eliminates the toxic and flammable characteristics of ethylene oxide while maintaining effective sterilization through the generation of reactive oxygen and nitrogen species.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If complex plasma generation conditions are applied, then sterilization effect is achieved, but apparatus complexity and cost increase

Engineering Contradiction:
Improvesterilization effectVSAvoidapparatus complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the plasma generation system into distinct functional components: a plasma generator unit, a feed pipe system, and a sterilization chamber. This segmentation allows each component to be optimized independently and simplifies the overall apparatus design compared to integrated complex plasma generation systems, reducing both complexity and cost while maintaining sterilization effectiveness.

Inventive Principle:
Principle #1Segmentation

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 method is safe, economical, and suitable for industrial scale sterilization, producing high concentrations of reactive species efficiently and avoiding damage to objects, with no toxic residues or pollution.

Implementation Method 1

activating a plasma generator device disposed on at least one feed pipe leading into the sterilization chamber and configured to generate one or more gaseous compounds comprising a mixture of reactive oxygen species (ROS) and of reactive nitrogen species (RNS)

Methodology Applied
Scientific EffectPlasma: Plasma

Data Source

PatentEP3801647B1Sterilization method using plasma
Publication Date: 2025.07.23 ALMA MATER STUDIORUM UNIV DI BOLOGNA
  • EP3801647B1 patent drawingFigure 1~2
  • EP3801647B1 patent drawingFigure 3A~4B
  • EP3801647B1 patent drawingFigure 5

AI summary

Sterilization method using plasma for sterilizing objects, wherein it is provided to introduce the objects to be sterilized into a sterilization chamber (13) and covey toward the latter a flow of air coming from a feed pipe (17) on which a plasma generator device (12) is disposed able to generate one or more gaseous compounds comprising a mixture of reactive oxygen species (ROS) and of reactive nitrogen species (RNS) so that the air is the carrier fluid which conveys the gaseous compounds toward the sterilization chamber (13); the method also provides to control the electric power used to produce the plasma as a function of the composition and/or the quantity of reactive species present in the sterilization chamber (13).