As a Johns Hopkins electrical engineer, Jin U. Kang has spent years tinkering with lasers and optical fiber, studying what happens when light strikes matter. Now, he's taking on a new challenge: brain surgery.

More precisely, Kang is building a tool to help brain surgeons locate and get a clear look at cancerous tissue. In some cases, Kang says, this device could eliminate the need to cut into the brain for a traditional biopsy, a procedure that can pose risks to the patient.