Pneumatic soft robot actuators made in single casting

In their solution, moulds and sacrificial water-soluble hollow cores are printed using fused filament fabrication. The team’s findings are detailed in Cyborg and Bionic Systems.

Bio-inspired soft robots have shown the ability to handle uncertainty and adapt to unstructured environments. However, their availability is partially restricted by time-consuming, costly, and highly supervised design-fabrication processes, often based on resource-intensive iterative workflows.

“We propose fabricating soft actuators using widely available and affordable processes, combining single step cast moulding with the FFF printing of sacrificial water-soluble cores. The actuator’s mechanical operability is defined through FEA using a nonlinear hyperplastic material model,” study author Professor Pedro Neto said in a statement.

Although the use of sacrificial mould cores is common in the fabrication of soft actuators, this process is highly dependent on the chamber geometry and requires specific conditions such as the solvent temperature and flow, among other factors.

“We propose a heated water circuit to speed up the dissolution of the hollow core’s material, ensuring complete removal from the actuator’s walls, even for intricate chamber geometries,” said the study authors.