Electrically Driven Tunable Microlenses

Unlike traditional glass lenses, focal lengths of microlenses can be tuned electrically or mechanically by various mechanisms. In this chapter we will describe a series of electrically tuned microlenses (1) liquid lenses covered with a thin polymer film and driven by electrostatic forces (2) lens arrays utilizing dielectrophoretic effect (3) electrochemically activated liquid lenses (4) tunable liquid lenses actuated by electrowetting and (5) liquid crystal (LC) lenses. 

Miniaturizing optical systems has been an active field of endeavor in recent years. The most important components in all optical systems are their lenses. In many cases, changing the focal distance of a system involves adjusting the whole system. However, such on-the-fly adjustments are often hard to realize for miniaturized systems. Developing miniature structures for tunable focus microlenses with variable focal lengths has attracted great interest. Many methods such as electrical fields and mechanical forces have been investigated. In this chapter, we will discuss electrically driven tunable microlenses. 

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Unlike traditional glass lenses, focal lengfhs of microlenses can be tuned by various electrical and mechanical techniques. Chapter 5, Electrically Driven Tunable Microlenses, describes several examples of electrically tuned microlenses including liquid-crystal-based lenses and liquid lenses driven by electrostatic forces, dielecfrophorefic forces, electrowetting, and electrochemical reactions. 

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