title: Optofluidic variable-focus lenses for light manipulation.
abstract: This paper presents a planar optofluidic lens for light manipulation utilizing a combination of optofluidic biconvex lens with micromixer. Three light manipulation techniques including tunable optical diverging, collimating and focusing are realized by altering the refractive index of the optofluidic variable-focus lenses formed by solid polydimethylsiloxane (PDMS) walls and tunable liquid lens body. The optical power from the laser input can be increased or decreased with the tuning of the variable-focus lenses' refractive indexes. The optical power adjustment capabilities are demonstrated and characterized. The combinations of benefits of all lens' optical manipulation capabilities, greater mechanical stability, significant increase of optofluidic device's life time and seamless integration with other lab-on-a-chip functionalities provide a promising and versatile optofluidic compartment to integrate with lab-on-a-chip excitation and sensing applications. Optofluidic lens-including system for tunable fluorescence sensing is demonstrated showing 186% increase in detected fluorescence intensity.
authors.affiliation: Applied Mechanics Laboratory, Department of Mechanical Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576. g0801405@nus.edu.sg
authors.forename: Y C
authors.initials: YC
authors.lastname: Seow
authors.forename: S P
authors.initials: SP
authors.lastname: Lim
authors.forename: H P
authors.initials: HP
authors.lastname: Lee
mesh_terms: D052160:Benzothiazoles / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D005453:Fluorescence; D007909:Lenses; D008027:Light; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D055095:Optics and Photonics / Q000295:instrumentation*; D012031:Refractometry
chemical_list: D052160:Benzothiazoles; D004129:Dimethylpolysiloxanes; C013830:baysilon; C005465:benzothiazole