Fig. 4: Manipulation of grippers.

a Schematic illustration of the fabrication and actuation of the gripper. b Dependence of swelling ratio of BSA microstructures on SL. The insets are microscopic images of BSA blocks fabricated under different conditions and actuated under different pH values. c Microscopic images of grippers with different BSA muscles (SL = 100 nm, SL = 150 nm, SL = 200 nm) at pH=1, pH=5 and pH=13, respectively. d Schematic diagram of the microfluidic system for manipulating the gripper. e Photograph of the real microfluidic chip for the TGoF system. f Actuation of the gripper by switching the pH values. g Gripping the Y-shape structure. h Pulling the Y-shape structure through the closed gripper. Source data are provided as a Source Data file.