Goal
Rapid, safe disinfection of skin and chronic wounds to eliminate drug-resistant bacteria such as MRSA.
Problem
Hospital-acquired infections caused by antibiotic-resistant bacteria; lengthy hand-washing procedures; chronic wound contamination.
Concept Summary
A low-temperature, atmospheric-pressure plasma is generated by applying a high-voltage electric field across a dielectric slab and mesh electrode, ionising ambient air (and optionally argon). The plasma produces a cocktail of biologically active agents - ultraviolet photons, ozone, nitrogen oxides, hydrogen peroxide and free radicals - that kill bacteria while remaining harmless to human tissue. The device can disinfect skin in seconds and treat chronic wounds.
Detailed Description
The prototype consists of a dielectric plate sandwiched between a solid electrode and a wire-mesh electrode. When a high voltage (~=18 kV) is applied, strong electric fields generate nano- and microsecond discharges that partially ionise the surrounding air (or argon flow). The resulting cold plasma emits UV radiation and creates reactive oxygen and nitrogen species (ROS/RNS) such as O_3, NO_x, H_2O_2 and free radicals. These agents act synergistically to in bacterial cells while leaving mammalian cells largely unaffected. Two device variants were built: a handheld skin-disinfection unit for hands/feet and an argon-plasma torch for chronic wound treatment, allowing control of reactive-species density to maximise bactericidal effect and minimise cytotoxicity.
Principles
- Cold plasma generation
- High-voltage electric discharge
- Reactive oxygen and nitrogen chemistry
- Ultraviolet photon sterilisation
Scientific Domains
Materials
- Dielectric slab (unspecified polymer or ceramic)
- Metal electrode
- Wire mesh
- Argon gas (for torch variant)
- Ambient air (oxygen, nitrogen, water vapour)
Mechanisms of Action
- Generation of UV radiation that damages bacterial DNA
- Production of reactive species (ozone, NO_x, H_2O_2, radicals) that oxidise cellular components
- Selective cytotoxicity through controlled species density
Energy Sources
Applications
- Hospital hand hygiene
- Disinfection of public surfaces
- Treatment of chronic non-healing wounds
- Potential use for gum disease and body odour control
Claimed Performance
Disinfection of hands in ~12 seconds with a bacterial reduction factor of 10^6; daily hand-disinfection time reduced from 3-5 hours to ~10 minutes; safe for skin and chronic wounds.
Experimental Evidence
Prototype trials on human skin showed a million-fold reduction in bacterial load after 12 s exposure; cell studies demonstrated selective bacterial killing and human cell regeneration; results published in New Journal of Physics (2009) and reported by BBC News and PhysicsWorld.
Replication Status
Prototype devices have been built and tested in laboratory and limited clinical settings; no commercial scaling reported.
Limitations
- Requires high-voltage power supply
- Effectiveness limited to surface exposure
- Long-term safety on human tissue not fully established
- Scaling to mass production not yet demonstrated
