High-efficiency optical ultrasound generation using one-pot synthesized polydimethylsiloxane-gold nanoparticle nanocomposite

Photoacoustic generation is an attractive alternative to generate ultrasound due to its broad bandwidth and high frequency capabilities. However, the challenges in low generation efficiency need to be addressed. In order to address this issue, a one-pot synthesized polydimethylsiloxane-gold nanoparticle (PDMS/Au NP) nanocomposite was utilized to generate ultrasonic pulses excited by a nanosecond laser. The enhanced efficiency of the photoacoustic signal was investigated by varying the concentration and the thickness of the nanocomposite film. The optimal peak-to-peak amplitude of the acoustic signal was observed to be 189.49 kPa under the laser energy density of 13 mJ/cm(2) at 1.8 mm away from the nanocomposite film, when the thickness and the concentration of the film were 450 mu m and 1.79 wt. %, respectively. Furthermore, the efficiency of the photoacoustic generation was increased 3 orders of magnitude compared to the aluminum thin film. The results indicate that high photoacoustic generation efficiency could be achieved through the PDMS/Au NPs nanocomposite. (C) 2012 Optical Society of America