Design and Fabrication of a Sensorized Soft Actuator via Embedded 3D Printing

The application of soft sensors significantly enhances the functionality of soft robotics. However, most sensorized soft robots need to be fabricated by multi-step manual methods, which are cumbersome and time-consuming. Here, we design a sensorized pneumatic actuator and print it entirely without any molds or sacrificial support structures using multi-material embedded 3D (EMB3D) printing. This effective and economic strategy achieves the integrated manufacturing of the network of actuators and sensors and simplifies the design and fabrication process of soft robotics. The finite element analysis (FEA) simulations of actuator bending behaviors are conducted and the comparisons between simulations and experiments verify the effectiveness of EMB3D printing. The soft strain sensor integrated on the top surface can detect the bending angle of the actuator with good linearity and sensitivity. Furthermore, a sensorized soft gripper assembled with two printed actuators is used to grasp objects of different sizes. The integrated sensor can estimate the grasping state and estimate the size of the object potentially, which is essential for closed-loop feedback control.