High-gain and broadband in vivo amplifiers enabled by matched materials

, a bandwidth above 600 Hz at 0.6 V, and an ultralow power consumption down to 0.57 nW at 0.2 V. We further demonstrate in vivo amplification of mouse electrocorticographic (ECoG) signal with good biocompatibility and superior signal quality. This work establishes a general material-device-circuit framework and design guidelines for OECT-based amplifiers.