Optoacoustic Effect in a Hybrid Multilayered Membrane Deposited on a Hollow-Core Microstructured Optical Waveguide

Abstract

Modern imaging technologies, including optoacoustic endoscopy, are based on the optoacoustic effect. Much promise is offered by the all-optical fiber-based approach, because fiber has a miniature cross section, is highly sensitive, and can be used in a variety of imaging and therapeutic techniques. We developed a probe based on a hollow-core microstructured optical waveguide (HC-MOW) with a hybrid nanostructured membrane. The membrane consisted of a free-standing single-walled carbon nanotube film and a Bragg reflector, which can be used as a source and a detector of ultrasound. Membrane vibrations were excited with an IR laser pulse and were read out by recording the intensity of the reflected visible CW laser light. We explained the nature of the intensity modulation of the reflected light and supported our explanation with numerical simulations of the membrane’s vibration eigenfrequencies and thermal distribution. The membrane vibrations were also observed with raster-scanning optoacoustic mesoscopy. The transmittance of the HC-MOW between 400 nm and 6.5 μm and that of the hybrid nanostructured membrane in the NIR range enable potential optoacoustic sensing in the IR fingerprint region of biomolecules. This permits the optoacoustic probe to be used for medical endoscopic purposes.

Thermo-optics of gilded hollow-core fibers

“…2,5–10 Among a variety of applications, inner-core functionalization strategies have been increasingly explored. 1,6,11–14 While many different materials, including nanostructures, have been explored in this endeavor, 15–17 here we will concentrate on plasmonic metals, which are known for their capabilities to manipulate light below the classical diffraction limit. 17,18 Functionalization of hollow-core PCFs with silver and gold nanoparticles has been demonstrated.…”

Revealing the static and dynamic nanomechanical properties of diatom frustules—Nature's glass lace

“…To the best of our knowledge, there has been no report of a fundamental and systematic study of the relationship between the structural and topographic features of diatom shells as well as wet and air-dried cells containing organic material, and their mechanical characteristics under static and dynamic loading. Given the fact that the diatom frustule itself can be considered as a nanostructured membrane, the determination of the mechanical properties of both membranes and cells with all organic components present seems extremely important and necessary both from the point of view of fundamental research and from the point of view of the use of these systems as functional materials for new devices 44 . Inspired by nature, the combination of organic and inorganic components fits well with modern technologies such as Layer-by-layer assembly that can be readily applied to modify the inorganic substrate to fabricate multilayer composites 45 .…”

Carbon Nanotube Microscale Fiber Grid as an Advanced Calibration System for Multispectral Optoacoustic Imaging

“…It is essential because the modern OA mesoscopy and tomography devices resolution varies from several , to hundreds of micrometers, respectively. The potential ability of the CNT-based materials to absorb light in the visible and IR region makes them a promising candidate for multispectral OA test systems. − Moreover, string shape and mechanical properties of fibers, characterized by breakage resistance under up to 35% of strain, are prospective in terms of reliability . Due to these properties as well as high conductivity and specific surface area, CNT fibers have already found many applications, for example, in supercapacitors, , thermoacoustic loudspeakers, artificial muscles, − as a part of sensors, , smart textile, solar cells, , and as components of composites and wearable and flexible electronics. , Moreover, a 100 MHz bandwidth laser-generated ultrasound source, based on carbon-polymer nanocomposites, was shown to be used for hydrophone calibration …”