Development of a Mechanical Actuator for Active Lenses

Abstract

SummaryVariable focus lenses can vary their shape and consequently their focus when a stimulus is applied. This kind of lenses, on some applications, has advantages over the regular lenses because of their smaller size and weight. Different types of stimulus can be used to change the shape of these lenses; the element that applies the stimulus is called actuator. Lenses deformed by a mechanical force are interesting devices that work in a way similar to human eyes. The muscles around a human eye compress or relax its lens every time a focus change is needed. On this paper we describe a voice coil actuator that applies mechanical force over a flexible polymeric lens, changing its shape and consequently its focus. The applied force, the deformation of the lens and its convergence power are functions of the driving current in the voice coil actuator. The maximum force applied by the actuator is 0.48N. The convergence power is also dependent of optical and viscoelastic properties of the lens material.