Objective and Impact Statement.Simultaneous imaging of ultrasound and optical contrasts can help map structural,functional,and molecular biomarkers inside living subjects with high spatial resolution.There is a need t...Objective and Impact Statement.Simultaneous imaging of ultrasound and optical contrasts can help map structural,functional,and molecular biomarkers inside living subjects with high spatial resolution.There is a need to develop a platform to facilitate this multimodal imaging capability to improve diagnostic sensitivity and specificity.Introduction.Currently,combining ultrasound,photoacoustic,and optical imaging modalities is challenging because conventional ultrasound transducer arrays are optically opaque.As a result,complex geometries are used to coalign both optical and ultrasound waves in the same field of view.Methods.One elegant solution is to make the ultrasound transducer transparent to light.Here,we demonstrate a novel transparent ultrasound transducer(TUT)linear array fabricated using a transparent lithium niobate piezoelectric material for real-time multimodal imaging.Results.The TUT-array consists of 64 elements and centered at~6 MHz frequency.We demonstrate a quad-mode ultrasound,Doppler ultrasound,photoacoustic,and fluorescence imaging in real-time using the TUT-array directly coupled to the tissue mimicking phantoms.Conclusion.The TUT-array successfully showed a multimodal imaging capability and has potential applications in diagnosing cancer,neurological,and vascular diseases,including image-guided endoscopy and wearable imaging.展开更多
We report a non-resonant piezoelectric microelectromechanical cantilever system for the measurement of liquid viscosity.The system consists of two PiezoMEMS cantilevers in-line,with their free ends facing each other.T...We report a non-resonant piezoelectric microelectromechanical cantilever system for the measurement of liquid viscosity.The system consists of two PiezoMEMS cantilevers in-line,with their free ends facing each other.The system is immersed in the fluid under test for viscosity measurement.One of the cantilevers is actuated using the embedded piezoelectric thin film to oscillate at a pre-selected non-resonant frequency.The second cantilever,the passive one,starts to oscillate due to the fluid-mediated energy transfer.The relative response of the passive cantilever is used as the metric for the fluid's kinematic viscosity.The fabricated cantilevers are tested as viscosity sensors by carrying out experiments in fluids with different viscosities.The viscometer can measure viscosity at a single frequency of choice,and hence some important considerations for frequency selection are discussed.A discussion on the energy coupling between the active and the passive cantilevers is presented.The novel PiezoMEMS viscometer architecture proposed in this work will overcome several challenges faced by state-of-the-art resonance MEMS viscometers,by enabling faster and direct measurement,straightforward calibration,and the possibility of shear rate-dependent viscosity measurement.展开更多
基金funded by the Penn State Cancer Institute—Highmark Seed Grant (SRK)College of Engineering Multidisciplinary Grant,and Grace Woodward Grant (SRK).
文摘Objective and Impact Statement.Simultaneous imaging of ultrasound and optical contrasts can help map structural,functional,and molecular biomarkers inside living subjects with high spatial resolution.There is a need to develop a platform to facilitate this multimodal imaging capability to improve diagnostic sensitivity and specificity.Introduction.Currently,combining ultrasound,photoacoustic,and optical imaging modalities is challenging because conventional ultrasound transducer arrays are optically opaque.As a result,complex geometries are used to coalign both optical and ultrasound waves in the same field of view.Methods.One elegant solution is to make the ultrasound transducer transparent to light.Here,we demonstrate a novel transparent ultrasound transducer(TUT)linear array fabricated using a transparent lithium niobate piezoelectric material for real-time multimodal imaging.Results.The TUT-array consists of 64 elements and centered at~6 MHz frequency.We demonstrate a quad-mode ultrasound,Doppler ultrasound,photoacoustic,and fluorescence imaging in real-time using the TUT-array directly coupled to the tissue mimicking phantoms.Conclusion.The TUT-array successfully showed a multimodal imaging capability and has potential applications in diagnosing cancer,neurological,and vascular diseases,including image-guided endoscopy and wearable imaging.
基金The work was partially supported by the Core Research Grant of the Science and Engineering Research Board,India.
文摘We report a non-resonant piezoelectric microelectromechanical cantilever system for the measurement of liquid viscosity.The system consists of two PiezoMEMS cantilevers in-line,with their free ends facing each other.The system is immersed in the fluid under test for viscosity measurement.One of the cantilevers is actuated using the embedded piezoelectric thin film to oscillate at a pre-selected non-resonant frequency.The second cantilever,the passive one,starts to oscillate due to the fluid-mediated energy transfer.The relative response of the passive cantilever is used as the metric for the fluid's kinematic viscosity.The fabricated cantilevers are tested as viscosity sensors by carrying out experiments in fluids with different viscosities.The viscometer can measure viscosity at a single frequency of choice,and hence some important considerations for frequency selection are discussed.A discussion on the energy coupling between the active and the passive cantilevers is presented.The novel PiezoMEMS viscometer architecture proposed in this work will overcome several challenges faced by state-of-the-art resonance MEMS viscometers,by enabling faster and direct measurement,straightforward calibration,and the possibility of shear rate-dependent viscosity measurement.
