Optimizing 3D printing process parameters for high-performance inflatable soft actuators

Inflatable actuators have shown great potential in soft robotics; however, the usage of 3D printing technologies is still at its infancy phase. This paper focuses on the usage of Material Extrusion (MEX) to advance the fabrication of soft inflatable actuators and enhance performance. Two different designs were studied and the softest thermoplastic elastomer available on the market was used. Printing parameters (i.e., infill direction, ironing and extrusion temperature) were investigated to maximize the elongation and improve the intra-layer adhesion which is crucial to achieve air-tightness. A design of experiments approach was used to analyze the effect of each process parameter on mechanical properties. Additionally, hyperplastic simulations were performed and benchmarked with experimental results. The relationship process parameters- mechanical properties- performance is evaluated, laying the foundation for a broader usage of MEX for the fabrication of soft inflatable actuators.