Georgopoulou Antonia, Michel Silvain, Clemens Frank
Department of Functional Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
Department of Mechanical Engineering (MECH), Vrije Universiteit Brussel (VUB), and Flanders Make Pleinlaan 2, B-1050 Brussels, Belgium.
Polymers (Basel). 2021 Apr 10;13(8):1226. doi: 10.3390/polym13081226.
Soft robotics and flexible electronics are rising in popularity and can be used in many applications. However, there is still a need for processing routes that allow the upscaling in production for functional soft robotic parts in an industrial scale. In this study, injection molding of liquid silicone is suggested as a fabrication method for sensorized robotic skin based on sensor fiber composites. Sensor fibers based on thermoplastic elastomers with two different shore hardness (50A and 70A) are combined with different silicone materials. A mathematical model is used to predict the mechanical load transfer from the silicone matrix to the fiber and shows that the matrix of the lowest shore hardness should not be combined with the stiffer fiber. The sensor fiber composites are fixed on a 3D printed robotic finger. The sensorized robotic skin based on the composite with the 50A fiber in combination with pre-straining gives good sensor performance as well as a large elasticity. It is proposed that a miss-match in the mechanical properties between fiber sensor and matrix should be avoided in order to achieve low drift and relaxation. These findings can be used as guidelines for material selection for future sensor integrated soft robotic systems.
软机器人技术和柔性电子技术越来越受欢迎，并且可用于许多应用中。然而，仍需要能够实现工业规模功能性软机器人部件生产扩大化的加工路线。在本研究中，建议采用液态硅橡胶注射成型作为基于传感器纤维复合材料的传感机器人皮肤的制造方法。将具有两种不同邵氏硬度（50A和70A）的热塑性弹性体传感器纤维与不同的硅橡胶材料相结合。使用数学模型预测从硅橡胶基体到纤维的机械载荷传递，结果表明，邵氏硬度最低的基体不应与较硬的纤维组合。传感器纤维复合材料固定在3D打印的机器人手指上。基于50A纤维复合材料并结合预应变的传感机器人皮肤具有良好的传感器性能以及较大的弹性。为了实现低漂移和低松弛，建议避免纤维传感器和基体之间的机械性能不匹配。这些发现可作为未来传感器集成软机器人系统材料选择的指导原则。
