Bioinspired Nanochannel-assisted Broadband Absorber for Solar Energy Harvesting

Solar absorber plates have limited applications as solar vapor interfaces because of their impermeability. Inspired by duckweed, we propose a four-layer solar absorber with nanochannels that allow water to pass through and numerically study its effectiveness. The bioinspired absorber achieves a solar energy harvesting efficiency as high as 99.4%. The ultra-high absorption of the bioinspired absorber in the solar spectrum is achieved by the coexistence of electric and magnetic polaritons, which are further enhanced by the bioinspired nanochannels. Most significantly, the nanochannels in the absorbers owning functions similar to those of duckweed to facilitate water transport from the lower region to the heated upper surface. The present study demonstrates an interesting strategy for fabricating solar absorbers with simple nanostructures and bioinspired nanochannels for water transportation, demonstrating potential applications in efficient solar steam generation for wastewater treatment and desalination.