Typically, microcomponents including actuators and mechanical structures are prepared in different places through different micromachining processes and then assembled into a functional microrobot (fig. The fabrication of untethered soft microrobots has revealed the limitations of conventional assembly and integration methods. This study may establish a new paradigm for microrobot integration and lead to the production of unique biohybrid microrobots with various advantages. To validate the method, we fabricated microrobots to elicit different motions and on-chip robots with unique characteristics for microfluidic applications. The proposed method allows the fast fabrication of microrobots through simple operations and affordable materials while providing versatile functions through the precise spatiotemporal control of in situ integration and reconfiguration of artificial muscles. In a microfluidic chip, hydrogel mechanical components and artificial muscle actuators are successively photopatterned from hydrogel prepolymer and biomolecular motors, respectively, and integrated in situ into functional microrobots. Here, we propose a method for fabricating microrobots in situ inspired by the construction of microsystems in living organisms. Nevertheless, the integration of microcomponents, especially the assembly of actuators and mechanical components, is still time-consuming and has inherent restrictions, thus limiting efficient fabrications of microrobots and their potential applications. Rapid progress has been achieved in developing miniaturized components for microrobotic systems, resulting in a variety of functional microactuators and soft components for creating untethered microrobots. Microrobots have been developed for applications in the submillimeter domain such as the manipulation of micro-objects and microsurgery.

Split second velocity serial code