Micro-Structured Water-Based Broadband Terahertz Pyramidal Absorber

The presence of multipath effects in terahertz wireless links degrades signal quality, making absorbers a critical component of 5G/6G wireless systems. Here, we leverage the innately high loss of liquid water, combined with the microscale precision of UV-cured resin-based micro 3-D-printing, to realize a viable pyramidal absorber for terahertz waves. Both simulation and experimental results confirm near-unity absorption, achieving over 99% in the 75−190 GHz range and 99.99% over 190−500 GHz. Furthermore, simulations show that the absorber maintains high performance up to 1000 GHz, with absorption exceeding 99.999%. These results demonstrate potential for future micro 3-D-printed resin-based absorbers that can be readily tailored to serve in communication, sensing, and radar applications thanks to their micro-scale size, cost-effectiveness, and adaptability to broadband terahertz wireless systems.