Investigation of Optical Ultrasound Emission Mechanism Based on CNTs-PDMS Composite

In this paper, we present an investigation into an optical ultrasound emission mechanism based on a composite of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS). The CNTs-PDMS composite was fabricated using a brush touch method with a multi-walled carbon nanotube (MWCNT) solution mixed with CNTs and isopropyl alcohol. To explore the optical ultrasound emission mechanism, three groups of specimens were fabricated. The first group was classified as having Nd:YAG laser spot sizes when using a convex lens. The second group was classified according to the coated thickness of the CNTs. Finally, the third group was classified according to the thickness of the PDMS. The CNTs-PDMS composite was placed in a water tank, and an Nd:YAG laser was irradiated onto the CNTs-PDMS composite to receive ultrasound waves generated using a hydrophone. A comparison of the results revealed that specimens with a small laser spot size, a thick coating of CNTs, and a thin PDMS layer achieved the highest frequency of ultrasound waves.