Baur Eva, Tiberghien Benjamin, Amstad Esther
Soft Materials Laboratory, Institute of Materials, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland.
National Center of Competence in Research Bio-Inspired Materials, Fribourg, 1700, Switzerland.
Adv Mater. 2024 Jun;36(23):e2313189. doi: 10.1002/adma.202313189. Epub 2024 Apr 4.
Fast advances in the design of soft actuators and robots demand for new soft materials whose mechanical properties can be changed over short length scales. Elastomers can be formulated as highly stretchable or rather stiff materials and hence, are attractive for these applications. They are most frequently cast such that their composition cannot be changed over short length scales. A method that allows to locally change the composition of elastomers on hundreds of micrometer lengths scales is direct ink writing (DIW). Unfortunately, in the absence of rheomodifiers, most elastomer precursors cannot be printed through DIW. Here, 3D printable double network granular elastomers (DNGEs) whose ultimate tensile strain and stiffness can be varied over an unprecedented range are introduced. The 3D printability of these materials is leveraged to produce an elastomer finger containing rigid bones that are surrounded by a soft skin. Similarly, the rheological properties of the microparticle-based precursors are leveraged to cast elastomer slabs with locally varying stiffnesses that deform and twist in a predefined fashion. These DNGEs are foreseen to open up new avenues in the design of the next generation of smart wearables, strain sensors, prosthesis, soft actuators, and robots.
软驱动器和机器人设计的快速发展需要新型软材料，其机械性能能够在短长度尺度上发生变化。弹性体可以被制成高拉伸性或相当坚硬的材料，因此在这些应用中具有吸引力。它们最常被浇铸，以至于其组成在短长度尺度上无法改变。一种能够在数百微米长度尺度上局部改变弹性体组成的方法是直接墨水书写（DIW）。不幸的是，在没有流变改性剂的情况下，大多数弹性体前驱体无法通过DIW进行打印。在此，引入了3D可打印双网络颗粒弹性体（DNGEs），其极限拉伸应变和刚度能够在前所未有的范围内变化。利用这些材料的3D可打印性制作了一个弹性体手指，其中包含被柔软外皮包围的刚性骨骼。同样，基于微粒的前驱体的流变特性被用于浇铸具有局部可变刚度的弹性体平板，这些平板会以预定义的方式变形和扭转。预计这些DNGEs将为下一代智能可穿戴设备、应变传感器、假肢、软驱动器和机器人的设计开辟新途径。
