Low-Temperature Dielectric Barrier Discharge Devices for Enhanced Surface Sterilization Using Cold Plasma and Chemical Agents

Background

Surface sterilization is a critical process in healthcare, food safety, and public hygiene, aiming to eliminate or inactivate harmful microorganisms such as bacteria, viruses, fungi, and spores from various surfaces. Traditional sterilization methods include chemical disinfectants, heat-based techniques (such as autoclaving or dry heat), and ultraviolet (UV) irradiation. While effective, these methods often present limitations: chemical disinfectants can leave toxic residues and may not be suitable for sensitive surfaces or human skin; heat-based methods require high temperatures that can damage heat-sensitive materials; and UV irradiation is limited by line-of-sight constraints and reduced efficacy on irregular or porous surfaces. As a result, there is a growing need for sterilization technologies that are effective, safe for a wide range of surfaces (including skin and delicate materials), portable, and capable of rapid disinfection without leaving harmful residues.

Current approaches to surface sterilization face several significant challenges. Chemical disinfectants, while widely used, can be hazardous to human health and the environment, and their overuse has contributed to the emergence of resistant microbial strains. Heat-based sterilization is energy-intensive, time-consuming, and unsuitable for many plastics, electronics, or fabrics. UV sterilization, although non-contact, is often ineffective in shadowed or creviced areas and can degrade certain materials over time. Furthermore, many advanced sterilization devices are bulky, require specialized infrastructure, or depend on external gas supplies, limiting their practicality for point-of-care or personal use. These limitations underscore the need for new sterilization solutions that combine efficacy, safety, versatility, and user convenience, particularly in settings where rapid, on-demand disinfection is essential.

Technology

The technology described is a low-temperature dielectric barrier discharge (DBD) device designed for effective surface sterilization using cold atmospheric pressure plasma (CAP). The device consists of flexible electrodes and dielectric layers—such as polyimide or PTFE—arranged to generate plasma in small gaps (≤2 mm) when powered by an AC high-voltage source (25–60 kHz, 1.6–3 kV) at low current (≤2 mA) and safe operating temperatures (22–40°C). The plasma produced contains reactive oxygen and nitrogen species (ROS/RNS), UV radiation, electric fields, and currents, all of which work together to inactivate bacteria, viruses, fungi, and spores on various surfaces, including skin, textiles, and medical equipment. The device can be configured with semipermeable layers, enclosures, or chemical reagent layers (such as water or hydrogen peroxide) to enhance plasma chemistry and sterilization efficacy. Flexible, portable, and scalable, the device is designed for safe, user-friendly operation without the need for external gas supplies.

This technology is differentiated by its unique combination of flexible, low-temperature plasma generation and the ability to synergistically amplify sterilization through the integration of chemical reagents. Unlike traditional sterilization methods that may require high temperatures, toxic chemicals, or complex infrastructure, this DBD device operates safely at ambient temperatures and low currents, making it suitable for direct use on sensitive surfaces and even human skin. The inclusion of chemical reagent layers, such as hydrogen peroxide, enables advanced oxidation processes—like the peroxone reaction—resulting in rapid and highly effective microbial inactivation. Experimental results demonstrate significant reductions in bacterial and viral loads within minutes, outperforming plasma or chemical treatments alone. The device’s modular design, long-term stability, and adaptability for handheld or large-area applications further set it apart, offering a versatile and powerful solution for modern sterilization challenges.

Benefits

• Effective sterilization of bacteria, viruses, fungi, and spores on diverse surfaces including skin, textiles, metals, and medical materials.
• Operates at low temperatures (22–40°C) and low currents (≤2 mA), ensuring safety and suitability for handheld, portable use.
• Flexible and scalable device design enables treatment of large or irregular surfaces and integration with chemical reagents for enhanced sterilization.
• Generates reactive oxygen and nitrogen species (ROS/RNS), UV radiation, and electric fields that synergistically inactivate microbes.
• Incorporation of chemical reagent layers (e.g., hydrogen peroxide) amplifies plasma chemistry, accelerating and improving disinfection efficacy.
• Produces UV-C radiation through gas-filled volumes to further enhance microbial inactivation.
• Demonstrated long-term operational stability and compatibility with control circuitry for temperature monitoring and safety shut-offs.
• Does not require external gas supplies or complex power sources, simplifying deployment and use in varied environments.

Applications

• Medical device surface sterilization
• Personal protective equipment decontamination
• Textile and clothing disinfection
• Human skin antimicrobial treatment
• Portable electronics sanitization

Additional info

These low-temperature dielectric barrier discharge (DBD) systems generate cold atmospheric pressure plasma for surface sterilization. Comprising flexible electrodes and dielectric layers, they capacitively produce reactive species, UV, and electric fields in small gaps. Powered by AC high-voltage (25-60 kHz, 1.6-3 kV) at low current and temperature (22-40°C), they inactivate microbes on various materials, optionally enhanced by chemical reagents.