Fabrication of Polydimethylsiloxane Microlenses Utilizing Hydrogel Shrinkage and a Single Molding Step

Micromachines

Bader Aldalali¹  Aditi Kanhere¹  Jayer Fernandes¹  Chi-Chieh Huang¹ 

[1] Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI 53707, USA; E-Mails:

关键词: microlenses;    microlens arrays;    compound eye;    tunable lenses;    hydrogels;   

DOI  :  10.3390/mi5020275

来源: mdpi

【 摘 要 】

We report on polydimethlysiloxane (PDMS) microlenses and microlens arrays on flat and curved substrates fabricated via a relatively simple process combining liquid-phase photopolymerization and a single molding step. The mold for the formation of the PDMS lenses is fabricated by photopolymerizing a polyacrylamide (PAAm) pre-hydrogel. The shrinkage of PAAm after its polymerization forms concave lenses. The lenses are then transferred to PDMS by a single step molding to form PDMS microlens array on a flat substrate. The PAAm concave lenses are also transferred to PDMS and another flexible polymer, Solaris, to realize artificial compound eyes. The resultant microlenses and microlens arrays possess good uniformity and optical properties. The focal length of the lenses is inversely proportional to the shrinkage time. The microlens mold can also be rehydrated to change the focal length of the ultimate PDMS microlenses. The spherical aberration is 2.85 μm and the surface roughness is on the order of 204 nm. The microlenses can resolve 10.10 line pairs per mm (lp/mm) and have an f-number range between f/2.9 and f/56.5. For the compound eye, the field of view is 113°.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.