Multilayered carbon nanotube yarn based optoacoustic transducer with high energy conversion efficiency for ultrasound application

Carbon Nanotube assemblies are currently of considerable interest for their properties of high-packing-density and aligned configurations, which offer a promising route to achieve higher strength and conductivity in macroscopic materials. While most researches have focused on their mechanical and electrical properties, recently, their light absorption and thermal conductivity have attracted more and more attention. This work introduces a novel freestanding optoacoustic transducer using continuous multilayered carbon nanotube yarns, gold nanoparticles and elastomeric polymer, which can be used for efficient conversion from laser energy to acoustic power and generating high acoustic pressure (~33.6 MPa) without focusing. The calculated energy conversion efficiency is as high as 2.74 × 10⁻². Such excellent performances could be attributed to its freestanding structure and the enhanced optical absorption due to localized surface plasmon resonance (LSPR) caused by gold nanoparticles. The laser-generated ultrasound has been experimentally demonstrated to be capable of manipulating micro particles (50 µm) in a transparent channel.