An auto-focus lens actuator using ionic polymer metal composites: Design, fabrication and control

Ionic polymer metal composites (IPMCs) are attractive smart materials. We propose an auto-focus (AF) lens actuator using IPMCs for cellular phones. In order to ensure stability, IPMCs were fabricated by using a plasma surface treatment and an ionic liquid solvent. AF lens actuator using IPMCs was designed to implement a large displacement and increased force by using a curved IPMCs. And the actuator had a structure with two springs to ensure stable AF actuation. Subsequently, a prototype AF lens actuator was fabricated. The parameters of the actuator were estimated from experimental data and a linear model of the AF lens actuator system. Then, a proportional-integral-derivative controller was designed, and the motion of the AF lens actuator was demonstrated through simulations and experiments.