Penn State researchers have developed a monolithic 3D chip that operates entirely on ambient light without using a battery. The integrated circuit is capable of performing calculations and sensing chemicals while harnessing solar power, minimizing the need for frequent battery replacements in remote locations.
The chip features a design that stacks silicon photovoltaics, MoS₂/WSe₂ complementary logic, and graphene chemical sensors within approximately 50 nanometers of each other. This compact arrangement reduces board area requirements, wiring losses, and latency associated with traditional battery-powered systems.
Engineers increasingly seek battery-free electronics that utilize renewable power to address the demands of long-lasting Internet of Things (IoT) and edge computing systems. Saptarshi Das, one of the authors of the research, stated, “We showed that heterogeneous materials—silicon, graphene, MoS₂, and WSe₂—can be integrated monolithically in three dimensions to create a self-powered sensing and computing system.”
The graphene sensors detect liquids and send electrical signals to the logic layer, where data is processed. The silicon photovoltaic module at the bottom converts ambient light into electricity to power the device. This approach significantly skips parts of traditional device architecture.
The development not only demonstrates the capabilities of a compact battery-free chip but also opens the door for larger 2D circuits that could incorporate similar design principles. Future applications may center on powering IoT systems in locations where battery access for maintenance is challenging.
