Mobile devices combined with aspheric-microscopic PDMS lenses with mechanically tunable structure and fluid lenses

• Main Authors: Pin-Wen Chen, 陳品文
• Other Authors: Yiin-Kuen Fu
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/23498330989209546910

碩士 === 國立中央大學 === 光機電工程研究所 === 103 === This paper mainly research the optical properties of aspheric lens and fluidic lens. (1)Mechanically tunable aspheric lenses via additive manufacture of hanging elastomeric droplets for microscopic application Mechanically deformable lenses with capability of dynamically tuning of focal lengths are presented. The fabricated 5 types of aspheric polydimethylsiloxane (PDMS) lenses present here have an initial focal length 7.0mm, 7.8mm, 9.0mm, 10.0mm, and 10.2mm, respectively. Incorporating two modes of operation in biconvex and concave-convex configurations, the focal lengths can be tuned dynamically as 5.2mm-10.2mm, 5.5mm-9.9mm, 6.6mm-11.9mm, 6.1mm-13.5mm, and 6.6mm-13.5mm respectively. Additive manufacturing is utilized to fabricate 5 types of APLs via sequential layering of materials. Complex structures with three dimensional features and shorter focal lengths can be successfully produced by repeatedly depositing, inverting and curing of controlled volume onto previously cured PDMS droplets. Through our experiments, we empirically find a direct dependence between that the changed in the focal lengths of the lenses and the amount (volume) of deposited droplets. The moldless low cost and flexible lenses fabrication method are able to transform an ordinary commercial smartphone camera into a low-cost portable microscope. A few microscopic features can be readily visualized such as wrinkles of ladybird pupa and printed circuit board. The fabrication technique by successively applying hanging droplet and facile mechanical tuning setup can be easily adopted and mass produce in the development of high performance optical lenses. (2)A novel dual-function lens with microscopic and vari-focus capability incorporated with an aberration-suppression aspheric lens Substantial aberrations are ubiquitous in many conventional adaptive lenses due to the existence of deformable interface and thus inevitably compromises the optical performance. In this paper, we introduce a novel concept of dual-function fluidic lenses (DFFL) with a built-in aspheric polydimethylsiloxane lens (APL) to enable the design of a compact optical systems with tunable imaging and aberration suppression properties. This is achieved by varying both hydrostatic pressures (i.e. adjusting the injected liquid volume change) such that a widely tunable focal length and the simultaneously integrated APL for aberrations correction. DFFL can transform to 4 modes: microscopic mode (APL only), APL/concave mode, APL/plano mode, and APL/convex mode. Focal tunability of DFFL from 12/8 mm to about 90/65 mm (DI water/ethanol) is demonstrated without any mechanical moving components. Aberration characterization is carried out systematically and the low cost, high performance microscopic mode can be easily achieved by actuating the contact between APL and PDMS membrane. In addition, DFFL turning to microscopic mode (focal length 7.32 mm and magnification 50X) can rival the images quality of commercial microscopes.