Tubular Optofluidics

• Applicant: Professor Dr. Hans Zappe
• Subject Area: Microsystems
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 259171179

• Final Report Year: 2019

Final Report Abstract

The aim of the project “Tubular Optofluidics” was to transform optofluidics into the third dimension. Through the realization of a cylindrically-symmetric multi-component optofluidic system in a tube, this new technology permits complex optical functionality using tunable all-liquid optics in a compact three-dimensional system. In contrast to stateof-the-art optofluidic concepts now extant, Tubular Optofluidics is not restricted to planar arrangements and thus represents an important step in incorporating tunable liquid optics into classical optical instrumentation, such as endoscopes and compact imagers. The project showed that optofluidics can be realized in a cylindrically-symmetric tubular arrangement. The technology is based on a flexible foil, fabricated using standard planar microsystems techniques, which provides fluidic, electrical and optical functionality. Using novel assembly processes, this foil is wrapped into the interior of a cylindrical tube and selectively filled with precisely defined volumes of various liquids, positioned axially using fluidic structures and patterned hydrophobicity on the foil. These liquid phases are configured to realize a variety of optical components, including lenses, apertures and prisms, all of which whose optical characteristics are tunable. Using a fluidic actuation technique known as electrowetting, the fluidic components can be tuned, allowing the realization of cylindrically-symmetric tunable apertures, tunable focus or zoom systems and axial as well as lateral scanning. Based on this technology, a focus-tunable lens; a lens with tunable astigmatism; a completely fluidic rotational beam scanner; a tunable fluidic aperture; and a multi-component zoom system using two independently tunable liquid lenses have been demonstrated. These ultra-miniaturized optical systems with no mechanically moving parts represent an entirely new generation of tunable micro-optical components for compact imaging systems.

Publications

• “Optofluidic laser scanner based on a rotating liquid prism,” Applied Optics, vol. 55, no. 9, pp. 2136–2142, 2016
  D. Kopp, L. Lehmann, and H. Zappe
  
• “Tubular astigmatism-tunable fluidic lens,” Optics Letters, vol. 41, no. 12, pp. 2735–2738, 2016
  D. Kopp and H. Zappe
  
• “Tubular focus-tunable fluidic lens based on structured polyimide foils,” IEEE Photonics Technology Letters, vol. 28, no. 5, pp. 597–600, 2016
  D. Kopp and H. Zappe
  
• “All-liquid dual-lens optofluidic zoom system,” Applied Optics, vol. 56, no. 13, pp. 3758–3763, 2017
  D. Kopp, T. Brender, and H. Zappe
  
• “Three-dimensional all-fluidic imaging systems,” in Technical Digest of the 22nd Microoptics Conference (MOC’17). Japan Society of Applied Physics, 2017, pp. 116–117
  D. Kopp, T. Brender, A. Dorn, L. Lehmann, and H. Zappe
  
• “Tubular astigmatism-tunable fluidic lens based on a flexible polymide foil,” in Proceedings of the 2016 IEEE Photonics Conference. IEEE, 2017; pp. 250–251
  D. Kopp and H. Zappe
  
• “Tubular optofluidics as a versatile optical toolbox,” in Proceedings of the 19th International Conference on Solid-State Sensors, Actuators and Microsystems (Transducers ’17). IEEE, 2017, pp. 866 – 869
  D. Kopp, L. Lehmann, T. Brender, A. Dorn, and H. Zappe