Heated Syringe Extrusion for Soft Gripper Fabrication in Additive Manufacturing

This study explores the feasibility of creating a pneumatically driven soft gripper using Thermoplastic Polyurethane (TPU) through Direct Ink Writing (DIW) technology via a heated syringe extrusion process. Unlike traditional DIW methods that do not involve heating, this approach allows for the extrusion of heat-sensitive materials like TPU, thereby broadening the potential applications of additive manufacturing. The soft gripper was designed based on prior research, and key fabrication parameters—such as temperature, pneumatic pressure, and nozzle diameter—were optimized. The resulting soft gripper was assessed for its mass, surface quality, and bending performance. The findings indicated that the soft gripper produced through heated syringe extrusion exhibited surface characteristics and mass comparable to those made using conventional Fused Filament Fabrication (FFF) techniques. Additionally, bending performance tests demonstrated that the gripper could be predictably controlled through pneumatic pressure, achieving bending angles consistent with previous studies. These results suggest that heated syringe extrusion is a viable method for producing high-quality TPU-based soft robotic devices, providing a cost-effective and versatile solution within flexible manufacturing systems.