Wireless Intraocular Microrobots: Opportunities And Challenges

Many current and proposed retinal procedures are at the limits of human performance and perception. Microrobots that can navigate the fluid in the interior of the eye have the potential to revolutionize the way the most difficult retinal procedures are conducted. Microrobots are typically envisioned as miniature mechatronic systems that utilize MEMS technology to incorporate sensing and actuation onboard. This chapter presents a simpler alternative approach for the development of intraocular microrobots consisting of magnetic platforms and functional coatings. Luminescence dyes immobilized in coatings can be excited and read wirelessly to detect analytes or physical properties. Drug coatings can be used for diffusion-based delivery, and may provide more efficient therapy than microsystems containing pumps, as diffusion dominates over advection at the microscale. Oxygen sensing for diagnosis and drug therapy for retinal vein occlusions are presented as example applications. Accurate sensing and therapy requires precise control to guide the microrobot in the interior of the human eye. We require an understanding of the possibilities and limitations in wireless magnetic control. We also require the ability to visually track and localize the microrobot inside the eye, while obtaining clinically useful retinal images. Each of these topics is discussed.