"BIO-ELECTRONICS: Replaceable Eyeball"
'Bionic eye' builds on prostheses milestones with an implanted artificial sight organ as the goal. Eye-implant technology is fighting a tough battle in the human body. Germs, infections, caustic body fluids, nerve degeneration, toxic reactions to chip-generated heat and the conflicting needs for high speed and ultralow power conspire against it. Nevertheless, scientists worldwide are hard at work on various projects to cure blindness, making it likely that many of these problems will be solved within the next 20 years. Pure medical science also promises solutions within 20 years-specifically, the ability to regress the DNA in dead retinal cells so that they regenerate themselves. Within 10 years, medical science also promises to perfect transplanting living retinal cells harvested from organ bank donors. In case that doesn't happen, the electronics industry is promising prostheses that outperform "original equipment" with every imaginable enhancement-from zooming to infrared to textual annotation and memory augmentation. But before these enhancements can be realized, two huge engineering problems face retinal implants, said Gene Frantz, principal fellow at Texas Instruments Inc. One is their interface to neurons; the other is the heat they generate. "How do you create a wetware interface-how do you connect electronics through the skin and inside the eye without introducing germs, paths for infection and other similar problems?" Frantz asked. "This is not a straightforward microelectronics problem, because you have to mimic biology in order to give the brain a better chance at 'seeing' with an artificial retina," said Mark Humayun, director of the National Science Foundation-sponsored Biomimetic MicroElectronic Systems Engineering Research Center at the University of Southern California. "Everything must be customized so it can mate with neurons-the packaging, the electronics, the software and everything else."