“We are integrating sensors in the exact place from which we want to receive information,” said McShane, professor of biomedical engineering and department head. “We don’t have to do a physical collection or any kind of penetration of the tissue. We can transmit light to the material—even through skin in the case of implants—and it will allow us to noninvasively monitor what is going on inside.”

The sensor particles are phosphorescent, meaning they absorb and then emit light, much like the glow-in-the-dark materials used in children’s toys. When exposed to light from an inexpensive red LED, the sensor particles absorb that light and then emit their own, modified by their surroundings. The entire process lasts only milliseconds—too fast for the human eye to detect—but provides optical sensor equipment with a wealth of information.