Fabrication and thermo-mechanical evaluation of a polyurethane-based porous structure intended for use in robotic gripping applications

Abstract

This study explores the design, manufacturing, and mechanical performance of a polyurethane-based porous component intended for use in robotic gripping applications. A sacrificial molding technique was employed, utilizing 3D-printed polyvinyl alcohol (PVA) lattice structures to form a counter gyroid framework. After infusing the lattice with polyurethane resin and dissolving the PVA in water, a lightweight and flexible gripper structure was obtained. The mechanical behavior of the gripper was evaluated through compression testing at varying temperatures (20 °C, 60 °C, 100 °C, and 140 °C) to analyze its load-bearing capacity, deformation response, and failure mechanisms. The experimental results revealed that while the gripper maintains high mechanical integrity at room temperature, its stiffness and strength decrease significantly with increasing temperature. Force-displacement curves, energy absorption analysis, and thermal imaging further demonstrated the gripper’s thermal sensitivity and potential application limitations in high-temperature environments. A flame resistance test confirmed the material’s low thermal conductivity and partial structural resilience under direct heat exposure, suggesting its potential suitability for handling moderately hot objects or applications involving short-term thermal exposure in industrial and soft robotics settings. Despite its flexibility and adaptability, the gripper’s limited thermal stability necessitates further material improvements to extend its usability under sustained high-temperature conditions.