Retinal implants can already restore sight to people who have lost it owing to degenerative eye diseases like macular degeneration or retinitis pigmentosa. Now new research suggests a way to make higher-quality, more biocompatible retinal implants by integrating living neural cells with a soft organic polymer semiconductor.
A retinal implant restores vision by sending a signal from a video camera attached to a pair of glasses to electrodes implanted on the back of a person's retina. But the silicon or platinum components typically used to for the electrodes tend to produce images of limited quality, and can leave the retina scarred.
Organic semiconducting polymers are softer and more flexible than silicon, and they have useful mechanical and electrical properties, making them ideal for biomedical applications. In fact, they are already used in some medical devices such as glucose sensors and the electrodes that record neural activity in the brain. Researchers at the Italian Institute of Technology have now shown how organic polymer could be used to make better electrodes for retinal implants.