Structural optimization and performance analysis of 3D-printed pneumatically operated soft actuators

Abstract

Soft actuators are an emerging field driven by breakthroughs in the production of soft materials with deformation properties suitable for grabbing, picking, and other specialized industry operations. In the present work, a design of the experiment was used to optimize the chosen parameters, and a soft pneumatic actuator was made utilizing the most suitable and flexible material via the fast-prototyping approach. Computational simulations were adopted for soft pneumatic actuators with varying shapes, materials, groove numbers, and channel thicknesses. The semioval-shaped actuators deformed more than the rectangular and triangular-shaped actuators did, and a semioval-shaped soft actuator achieved a maximum deformation of 6.09 cm. The number of grooves increased to 10, 15, and 20, with a greater number of grooves causing greater distortion in the soft actuator. However, the 15-grooved actuator was the best, with a maximum deformation of 5.6 cm. The size of the pressure inlet channel is very important when directing the air pressure in the soft actuator. Thus, the soft actuator had tolerable and controlled deformation at the optimum of a 2 mm thick channel. Acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), and thermoplastic polyurethane (TPU) materials were selected for numerical analysis; TPU materials are more suitable and flexible materials for the development of soft actuators. The TPU material was accurately printed via appropriate printing parameters and the fused deposition method. Its deformation behavior was investigated, and the results were compared between numerical and experimental measurements. The relative errors between the experimental and numerical output ranged from 5% to 23%, proving that it is challenging to arrive at a perfect solution. As a result, the task could be prolonged for further examination to achieve the greatest flawless deformation to satisfy the predicted result.