Strain tunable optics of elastomeric microlens array

Microlens arrays (MLAs) have attracted great attention with their important applications in many fields, such as optical communications, organic light emitting diodes (OLEDs), thin film photovoltaic cells, and novel bio-inspired devices. The dynamically tunable MLAs whose optical properties can be changed in a controllable manner are especially desirable in some recent developments. In this study, a very simple tuning method via mechanical stretching is proposed to tune the optics of elastomeric MLAs. Theoretical mechanics and optics studies are combined to demonstrate the tunability of elastomeric MLAs under both uniaxial and equibiaxial stretching. The results show that extremely large tuning range of the focal length can be achieved using this method. This theoretical study can provide important implications to not only the design of tunable MLAs, but also developments that require controllable optical elements.