The ability to deliver light into the body is important for laser surgery, drug activation, optical imaging, diagnosis of disease, and in optogenetics, the experimental field in which light is used to manipulate the function of neurons in the brain. Yet, delivering light into the body is difficult and typically requires the implantation of an optical fiber made of glass.
"The problem is that visible light can only penetrate to a certain depth, maybe hundreds of microns," said Jian Yang, professor of biomedical engineering, Penn State. "Near infrared light might be able to penetrate a few millimeters to a centimeter, but that is not enough to see what is going on."
Currently, people use glass fiber to get light into biological tissue at depth, but glass is brittle and is not biodegradable. It can break and damage tissue if implanted. Researchers are beginning to look toward flexible polymer fibers as a solution.