Thin-film transducers for the detection and imaging of Brillouin oscillations in transmission on cultured cells

摘要

Mechanicalimagingandcharacterisationofbiologicalcellshasbeenasubjectofinterestforthelasttwentyyears.Ultrasonicimagingbasedonthescanningacousticmicroscope(SAM)andmechanicalprobinghavebeenextensivelyreported.Largeacousticattenuationathighfrequenciesandtheuseofconventionalpiezo-electrictransducerslimittheoperationalfrequencyofaSAM.Thislimitationresultsinlowerresolutioncomparedtoanopticalmicroscope.Directmechanicalprobingintheformofappliedstressbycontactingprobescausesstresstocellsandexhibitspoordepthresolution.Morerecently,laserultrasoundhasbeenreportedtodetectultrasoundintheGHzrangeviaBrillouinoscillationsonbiologicalcells.Thistechniqueoffersapromisingnewhighresolutionacousticcellimagingtechnique.Inthiswork,wepropose,designandapplyathin-filmbasedopto-acoustictransducerforthedetectionintransmissionofBrillouinoscillationsoncells.Thetransducerisusedtogenerateacousticwaves,protectthecellsfromlaserradiationandenhancesignal-to-noiseratio(SNR).ExperimentaltracesarepresentedinwaterfilmsaswellasimagesoftheBrillouinfrequencyofphantomandfixed3T3fibroblastcells...