Miniaturized tunable apertures

Hochschulschrift

Zusammenfassung: During the last years the optical quality of cellphone cameras has steadily increased. Surprisingly though, even high-end smartphones still only have fixed apertures. To overcome this limitation and enable more versatile imaging, new technical approaches are required, as further downscaling of classical mechanical blade apertures is no longer feasible in the required size range.This work presents novel types of tunable apertures. The first approach is an optofluidic iris, based on the concentric actuation of an opaque liquid ring by electrowetting-on-dielectrics (EWOD). The implemented prototype demonstrates that the performance required for an application in the field of mobile cameras can be reached. A batch fabrication process is introduced as a basis for low-cost and high volume manufacturing of the device. The new prototype is shock resistant, shows excellent electrical reliability, has 7 actuation states, and is fast. Switching times to adjacent states are below 80 ms. This advanced optofluidic technology is also transferred to the new field of electrically tunable slit apertures: a scanning optofluidic slit and slit width tuning down to 3 μm is demonstrated.Besides, a completely new approach for a tunable iris is conceived by introducing liquid crystal elastomer (LCE) actuators. Similar to the human iris, the thermal LCE actuators contract radially to widen the aperture. For the iris, a new radial magnetic orientation technique and a novel heater technology are implemented to enable ultra-compact actuators. In a final step, both irises are integrated into a compact tunable camera system mimicking the human eye.The developed prototypes show a high potential for compact tunable apertures in portable devices. With the slit aperture, the range of potential applications of such devices is extended from the field of imaging and spatial filtering to spectral applications such as monochromators and hyper-spectral imaging systems

Angaben zum Objekt

• Standort: Deutsche Nationalbibliothek Frankfurt am Main
• Umfang: Online-Ressource
• Sprache: Englisch
• Anmerkungen: Albert-Ludwigs-Universität Freiburg, Dissertation, 2015

Klassifikation und Themen

• Klassifikation: Industrielle und handwerkliche Fertigung
• Schlagwort: Aperture 2 ; Fluidik ; Polymere ; Optik ; Mikroaktor

Beteiligte, Orts- und Zeitangaben

• Ereignis: Veröffentlichung
• (wo): Freiburg
• (wer): Universität
• (wann): 2016
• Urheber: Schuhladen, Stefan
• Beteiligte Personen und Organisationen: Zappe, Hans P.

Weitere Informationen

• DOI: 10.6094/UNIFR/10510
• URN: urn:nbn:de:bsz:25-freidok-105106
• Rechteinformation: Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Letzte Aktualisierung: 25.03.2025, 13:42 MEZ