SUMMARY

Electromagnet (EM) arrays have been widely used in many applications ranging from industrial motors to haptic devices in medical robotics. Motivated by an emerging need to help photoreceptor degeneration patients to restore vision, this research explores a new method utilizing magnetic/electric fields as media to enable the induction of a relatively high-resolution eddy-current pattern on an electrically conductive surface (for stimulation of retinal ganglion cells) with a relatively small number of EMs. Unlike traditional methods where discrete points are stimulated, the synthetized magnetic/electric fields are accurately controlled between adjacent EMs. To illustrate the fundamentals, this research develops the operational principle, mathematical models and design theory to control a two-dimensional (2D) EM array for moving its resultant magnetic flux density or induced eddy-current in a plane at high speed. A numerical investigation will be used as an effective means to illustrate the concept feasibility of continuous scanning system that converts optically captured image features into frame-based magnetic/eddy-current field patterns, and perform parametric studies which offer a basis for establishing design criteria and optimization. A laboratory prototype test-bed will then be developed for experimental verification of the design theory and for performance evaluation of the eddy-current scanning system. It is expected that this non-mechanical scanning system will have a broad range of applications. As an immediate application, the continuous eddy-current scanning design will be applied to a surface defect detection application.