Optical generation of high frequency ultrasound using two-dimensional gold nanostructure

A two-dimensional (2D) gold nanostructure is used to optically generate high frequency ultrasound. The structure consists of 2D arrangements of gold nanoparticles, sandwiched between a transparent substrate and a 4.5μm thick polydimethylsiloxane (PDMS) layer. The acoustic signal displays significant improvements compared to a bulk black PDMS films (the current state of the art) at frequencies from 50to100MHz. The high optical extinction ratio of the gold nanostructure provides a convenient method to construct an integrated transmit/receive optoacoustic array. These results show that a 2D gold nanostructure can be used to produce high frequency arrays for ultrasound imaging.