Reconfigurable folded reflectarray based on an active 1-bit metasurface and its application in microwave hyperthermia

Area of Science:

• Electromagnetic Engineering
• Biomedical Engineering
• Medical Physics

Background:

• Microwave hyperthermia offers a promising approach for cancer treatment by elevating tumor temperatures.
• Current methods for controlling hyperthermia applicators face challenges in achieving precise and adaptable focal spot targeting, especially for irregular tumor shapes.
• Reflectarray antennas, with their ability to shape electromagnetic fields, present a potential solution for advanced hyperthermia applications.

Purpose of the Study:

• To develop and validate an electronically reconfigurable folded reflectarray (ERFR) for real-time control of focal spots in microwave hyperthermia.
• To demonstrate the ERFR's capability in heating large-sized, irregular-shaped superficial tumors to therapeutic temperatures.
• To explore the potential of ERFR technology in advancing targeted cancer treatment through precise thermal management.

Main Methods:

• Design of an ERFR comprising an electronically reconfigurable polarization-conversion metasurface (ERPCM), a polarization-selective metasurface (PSM), and a feeding antenna.
• Integration of PSM to reduce the overall profile of the ERFR.
• Electrical control of phase compensation distribution on the ERPCM to steer the focal spot of the reflectarray.
• Simulation and experimental validation of the ERFR's heating performance on simulated tumor models.

Main Results:

• The ERFR successfully demonstrated real-time control of its focal spot by electrically adjusting the phase compensation on the ERPCM.
• Simulations and experiments confirmed the ERFR's ability to heat targeted sub-regions of a simulated tumor to therapeutic temperatures (above 40 °C).
• The proposed ERFR system effectively heated the entire simulated tumor by sequentially moving the focal spot across different sub-regions.

Conclusions:

• The developed ERFR provides precise and dynamic control over electromagnetic wave focusing, making it suitable for advanced microwave hyperthermia.
• The ERFR technology shows significant potential for treating large-sized and irregularly shaped superficial tumors with enhanced therapeutic efficacy.
• This study highlights the feasibility and effectiveness of using reconfigurable metasurfaces for targeted thermal therapies in oncology.