Conference Paper

An endoscope utilizing tunable-focus microlenses actuated through infrared light

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Abstract

We report on a prototype endoscope with tunable-focus liquid microlenses actuated through infrared (IR) light integrated at its distal end. Tunable-focus microlenses scanning the areas of interest with minimal movements of the scopes themselves would greatly advance endoscopy. Multiple IR light-responsive hydrogel posts were used to tune the focal length of the microlens, which were formed by a curved water-oil meniscus. The fabrication and actuation of the hydrogel posts were realized through light transmitted via optical fibers. The focal length varied from 52 mm to 8 mm. Focused images were obtained from an image fiber bundle. A microlens array with larger depth of focus and view of field could be potentially utilized.

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... Benefitting from variable focal length of the microlenses, different depth of focus and thus spatial depth perception can be obtained in the serial images acquired. Based on their accomplishment on liquid microlenses actuated through IR-light-responsive hydrogel described in the prior section, Zeng et al. demonstrated prototype endoscopes with tunable-focus liquid microlenses integrated at their distal ends and actuated through IR light [25,75]. Figure 12 shows the schematics of such a prototype endoscope [25]. ...
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