a, b, A microfluidic soft controller is pre-fabricated (a) and loaded into a mould (b). c–e, Matrix materials are poured into the mould (c) and fugitive and catalytic inks are EMB3D printed (d, e). Scale bar in e, 10 mm. f, After matrix curing, the printed fugitive inks auto-evacuate, yielding open channels. Scale bar, 2 mm. g, The octobot is removed from the mould and inverted to reveal a fully soft, autonomous robot that is controlled via the embedded microfluidic soft controller and powered by monopropellant decomposition. Scale bar, 10 mm. Fluorescent dyes have been added in e and g to assist in visualization of internal features.