Soft electrodes designed to perfectly match a person’s brain surface may help advance neural interfaces for neurodegenerative disease monitoring and treatment, according to a new study led by Penn State researchers. Neural interfaces are powered by tiny sensors capable of tracking biophysical signals, known as bioelectrodes. These sensors are usually made from stiff materials in a one-size-fits-all design that struggles to match the brain’s complex structure. The researchers have created a novel approach to 3D printing bioelectrodes that can stretch and morph to fit the minor differences that make every brain unique.