Fig. 3
From: 3D printing of robotic soft actuators with programmable bioinspired architectures
Soft actuators with programmed motion modes fabricated by multimaterial 3D printing of silicones. Actuators with bioinspired architectures are shown in a and b, whereas other multimaterial morphing configurations are displayed in c and d. a Contraction is achieved by printing stiff stripes along the long axis of a soft silicone tube (lead angle α = 0°), thereby restricting its elongation and only allowing for radial expansion. b A twisting motion is generated by winding the stripes around the soft inner tube with a lead angle of for example 45° with respect to the long axis. The twisting angle increases with the applied internal pressure. c Bending motion is obtained when a soft silicone with embedded air cavities is printed onto a stiff silicone film, restricting one side of the chambers from expansion when pressurized. Bending angles up to 90° are achieved at a pressure of 6 kPa. d A grabbing and sealing soft actuator was designed by printing a closed, stiff silicone cylinder with a concentric inner soft tube separated by an air cavity. When inflated, the inner tube deforms uniformly until mechanical instability leads to buckling and finally to a complete sealing of the central opening. e Load bearing capacity of grabbing and contractile soft actuators. Scale bars are 2 cm for a–d and 4 cm for e
