The innovation engine for new materials

Robert Salazar

Robert Salazar

Major: 

Physics

University: 

Santa Barbara Community College

Faculty Sponsor(s): 

Daniel Morse
Michael Gordon

Faculty Sponsor's Department(s): 

Chemical Engineering
Chemistry and Biochemistry

Project Title: 

Development of Photoacoustic Ultrasonic Transducers

Project Description: 

Nanostructuring a material’s surface to impede the flow of heat into the bulk of the material increases the intensity of its photoacoustic response from intensity modulated light. The rise time required for a nanostructured surface’s photoacoustic response to reach 90% of its maximum intensity, is short enough to allow ultrasound to be produced from a flashing light source. There are many applications in science and industry for sound production at ultrahigh frequencies. Ultrasound production at frequencies beyond 20MHz allows for imaging at resolutions high enough to assist in the diagnosis of skin and eye pathologies as well as incorporating genes into cells through sonoporation. Current theory of the photoacoustic effect has yet to incorporate the effect that surface structure has on the intensity and rise time of the acoustic response. This study aims to correlate surface structure, thermal conductivity, and light absorption with its effect on intensity and rise time. Understanding the role surface structure plays in acoustic generation will guide developments of a material that is optimized to produce high intensity ultrasound across a broad frequency range.