Bringing hard electronics into soft and squishy bodies

John A. Rogers, a professor at Northwestern University and director of the Querrey Simpson Institute of Bioelectronics, has spent his career figuring out how to make rigid silicon electronics work inside the soft, curved, moving tissues of the human body. His inventions include flexible brain probes, a pacemaker smaller than a sesame seed, and wireless sensors that stick to skin like temporary tattoos. But the path from hard electronics to biocompatible devices required rethinking not just materials, but the fundamental language of how electronics and biology communicate.

The origin story: from flexible displays to the brain

Rogers started his independent career at Bell Labs working on flexible electronics for applications like paper-like displays and ultra-low-cost electronic tags. When he moved to the University of Illinois, the Defense Advanced Research Projects Agency (DARPA) funded work on flexible electronic systems for field-deployable communication networks. The shift toward biocompatible electronics happened almost by accident. After giving a talk in electrical engineering at the University of Pennsylvania, several neurosurgeons who saw the title approached him and asked whether he had considered putting those flexible devices on a brain — "a very squishy market," as Rogers put it. That conversation launche