Construction of In Situ Heat Source Based on Microwave Absorbing Materials for Precise Energy Transfer and Conversion of Microwave Thermotherapy

ABSTRACT This study aims to solve the core bottleneck of microwave thermotherapy technology in energy transmission and conversion. To enhance the accuracy of energy transmission, a miniaturized waveguide aperture antenna based on the metasurface is introduced to achieve directional energy delivery to the target area, significantly improve the efficiency of energy deposition and reduce normal tissue damage. In terms of energy conversion, the microwave absorbing material with intrinsic high‐efficiency absorption characteristics (absorption rate >90%) in the 2.45 GHz medical frequency was innovatively designed to achieve microwave thermal conversion through its dielectric loss and magnetic loss mechanism, overcoming the limitations of traditional microwave‐sensitizing materials that rely on external conditions. By combining the miniaturized waveguide aperture antenna with microwave absorbing materials, a synergistic treatment system is constructed: the antenna ensures the accurate delivery of energy to the target area, and the microwave absorbing material acts as an in situ heat source to achieve efficient energy conversion. Through system simulation, preparation and performance evaluation, combined with in vitro experiments and animal model validation, the study confirmed that this strategy can significantly improve the accuracy, efficiency, and safety of microwave thermotherapy that promises to resolve the limitations of microwave thermotherapy.