Plasma Sterilisation Tip for Hydroxyl Radical Generation
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Solution Overview
Problem
Current sterilization methods are inadequate for effectively and efficiently eliminating microbial contamination in clinical and hospital environments, particularly due to the limitations of conventional disinfectants in terms of concentration, reaction time, and potential for pollution.
Innovation Solution
A sterilization device that generates and directs a stream of hydroxyl radicals by producing thermal or non-thermal plasma into a water mist, which is then applied to surfaces or objects, using a coaxial transmission line and energy delivery tip to create a high electric field and sustain plasma, allowing for efficient and pollution-free microbial elimination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional disinfectants are used for sterilization, then microbial elimination can be achieved, but the reaction time is long and harmful by-products are generated
Solution Approach 1:
The invention changes the chemical parameters by using hydroxyl radicals (•OH) instead of conventional disinfectants. These radicals have extremely high oxidation potential and react with microorganisms at much faster rates, reducing sterilization time from minutes or hours to seconds while eliminating harmful by-products through complete oxidation to CO2 and H2O
Solution Approach 2:
The invention employs hydroxyl radicals, which are the strongest known oxidizing agents, to accelerate the sterilization process. These radicals non-selectively oxidize cellular components of microorganisms (proteins, lipids, carbohydrates, nucleic acids) at extremely high reaction rates, achieving rapid microbial elimination without the slow action characteristic of conventional disinfectants
2Reliability
If conventional disinfectants are used for sterilization, then microbial elimination can be achieved, but harmful by-products and pollution are generated
Solution Approach 1:
Hydroxyl radicals completely oxidize microorganisms and organic matter to CO2, H2O, and simple inorganic salts, eliminating the formation of harmful disinfection by-products that characterize conventional disinfectant use. This complete oxidation pathway ensures high sterilization reliability without generating persistent harmful substances
Solution Approach 2:
The invention converts the potentially harmful high reactivity of radicals into a benefit by using it to completely mineralize organic pollutants and microorganisms. The same reactivity that could cause damage is harnessed to achieve complete destruction of pathogens and conversion of organic matter to harmless inorganic products
3Reliability
If high concentration disinfectants are used to improve sterilization effectiveness, then microbial elimination is enhanced, but toxicity and environmental pollution increase
Solution Approach 1:
The invention changes from using high concentrations of stable chemical disinfectants to generating hydroxyl radicals in situ at very low concentrations (10^-18 to 10^-21 mole fraction). These radicals achieve equivalent or superior sterilization effectiveness through their extremely high reaction rate constants with microorganisms, while their short lifetime prevents accumulation and reduces toxicity
Solution Approach 2:
Hydroxyl radicals function as short-lived, highly reactive intermediates that perform sterilization and then rapidly decay or react with ambient substances. This disposable nature of the radicals eliminates the need for persistent chemical residues, reducing long-term toxicity and environmental impact while maintaining high sterilization effectiveness during the brief period of action
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 device achieves rapid and effective sterilization by producing hydroxyl radicals that are 1000 times more effective than conventional disinfectants, with a biochemical reaction time of about 1 second and lethal density significantly lower than traditional disinfectants, ensuring efficient microbial elimination without harmful by-products.
Implementation Method 1
a coaxial transmission line mounted in the housing and arranged to convey radiofrequency (RF) and/or microwave frequency electromagnetic (EM) energy to the energy delivery tip
Implementation Method 2
an energy delivery tip configured to produce a thermal or non-thermal plasma
Implementation Method 3
The impedance at the hydroxyl radical generating region is controlled to be high to promote creation of an ionisation discharge which in turn generates hydroxyl radicals
Implementation Method 4
Hydroxyl radicals are far more effective at oxidizing pollutants in the air than ozone and are several times more germicidal and fungicidal than chlorine
Data Source
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AI summary
The invention relates to sterilisation systems suitable for clinical use. In particular, there is provided a sterilisation device comprising: a housing defining a water mist fluid flow path between an inlet for receiving water mist and an outlet for directing a flow of hydroxyl radicals towards a region to be sterilised; an energy delivery tip configured to produce a thermal or non-thermal plasma; a coaxial transmission line arranged to convey radiofrequency (RF) and/or microwave frequency electromagnetic (EM) energy; and a gas conduit in the housing and arranged to deliver gas to the energy delivery tip, wherein the energy delivery tip extends from a distal end of the coaxial transmission line. The energy delivery tip comprises: a first electrode electrically connected to an inner conductor of the coaxial transmission line; and a second electrode electrically connected to an outer conductor of the coaxial transmission line. The second electrode defines an internal volume of the energy delivery tip, wherein the first electrode extends longitudinally within the internal volume. The first electrode and second electrode are configured to: strike a plasma in the gas delivered to the energy delivery tip, and direct the plasma into the water mist fluid flow path to form hydroxyl radicals therein.