Researchers at the University of Pennsylvania built what they describe as a sub‑millimeter robot equipped with sensors, a motor and an onboard computer, powered by microscopic solar cells. The device moves through fluids by generating electric fields and can sense and respond to local environments, according to statements from lead researcher Marc Miskin. Each robot measures less than one millimeter and costs under a penny to produce; teams in adjacent labs are assembling and programming swarms while exploring cooperative behaviors. The research positions the devices for long‑term visions in biomedical applications, including potential minimally invasive procedures or in‑body sensing, though significant engineering and biocompatibility work remains. The advance highlights progress in miniaturized actuators, integrated microelectronics and energy harvesting for medical microrobotics and may spur new preclinical studies on delivery, control and safety in biological environments.