A thin robot made of flexible electronics for in-situ machining and inspection of large structures

In-situ machining and inspection of large structures drive demand, but conventional robots are typically heavy and bulky, potentially damaging fragile materials and limiting effectiveness in confined spaces or on complex surfaces. Here, we present a thin (970 µm), lightweight (19.7 g), and flexible robot powered by a two-degree-of-freedom electrostatic actuator made of flexible circuits. The actuator enables motion with 21.7 µm repeatability, a maximum speed of 290 mm/s, and a superposable output force up to 1.07 N. The robot follows arbitrary trajectories and operates reliably on diverse surfaces, including flat, curved, and vertical substrates, through electrostatic adhesive feet. It carries payloads up to 4.06 times its own weight and tolerates impact from a 3 kg weight. We demonstrate multifunctional in-situ operation through narrow-gap inspection, curved-surface grinding, and microscale electrical discharge machining. This establishes a thin, flexible platform for in-situ tasks in constrained and sensitive environments.