Fig. 4. In situ fabrication of hydrogel mechanisms and manipulators (a) the fabrication methodology for building multibody microsystems. Digital maskless lithography inside microchannels drives the polymerization of compliant mechanisms physically coupled to the actuators. (b) The rotation of a cantilever beam using a single MA serving as an active hinge. (c) The control of deformation of a microscale bending actuator using structured illumination. FEM analysis predicts the deformation patterns. (d) Lever system for controlling the transmission of stress and strain. (e) The schematic description of the geometrical design parameters in the lever system. (f) The change in the transmission angle θf–θi normalized with the initial value θi for two different lever arm designs. We compared two types of devices having the same transmission angle of 60° and varying arm length l (type I: 100 μm and type II: 250 μm). Experimental measurements (n = 8) are compared with the calculated values for the initial design parameters. (g) A cantilever system for measuring the force generated by a single actuator. (h) A cantilever system with a serial elastic spring connection. Spring deformation blocks force transmission to the cantilever. All scale bars represent 50 μm.
