Laser-induced ultrasound transmitters for large-volume ultrasound tomography

D Thompson; J R Nagel; D B Gasteau; S Manohar

doi:10.1016/j.pacs.2021.100312

Laser-induced ultrasound transmitters for large-volume ultrasound tomography

Photoacoustics. 2021 Nov 10:25:100312. doi: 10.1016/j.pacs.2021.100312. eCollection 2022 Mar.

Authors

D Thompson¹, J R Nagel¹, D B Gasteau¹, S Manohar¹

Affiliation

¹ Multimodal Medical Imaging (M3i) group, Technical Medical Centre, University of Twente, Netherlands.

Abstract

We present a protocol for the design, fabrication and characterisation of laser-induced ultrasound transmitters with a specific, user-defined frequency response for the purpose of ultrasound tomography of large-volume biomedical samples. Using an analytic solution to the photoacoustic equation and measurements of the optical and acoustic properties of the materials used in the transmitters, we arrive at a required mixture of carbon black and polydimethylsiloxane to achieve the desired frequency response. After an in-depth explanation of the fabrication and characterisation approaches we show the performance of the fabricated transmitter, which has a centre frequency of 0.9 MHz, 200% bandwidth and 45.8 $^{\circ}$ opening angle, multi-kPa pressures over a large depth range in water.

Keywords: Environmental applications of photoacoustics/laser ultrasound; Industrial; NDE; New transducers.